Subject: noise from aircraft question
From: Ron Thompson rlthompson@.................
Date: Sun, 30 Sep 2001 18:25:21 -0230
Late one recent night I realized that building a seismic detector
for my location may be a waste of time.
The airport is realitively close to the town, and that night the
departing aircraft were flying over the town. Some of the larger
aircraft rattle the windows, and shake the house. Is this type of
vibration likely to be detected on a seismograph?
Ron (in Gander, Newfoundland)
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: noise from aircraft question
From: CapAAVSO@.......
Date: Sun, 30 Sep 2001 19:41:00 EDT
In a message dated 9/30/01 9:52:05 PM GMT Daylight Time,
rlthompson@................. writes:
<< The airport is realitively close to the town, and that night the
departing aircraft were flying over the town. Some of the larger
aircraft rattle the windows, and shake the house. Is this type of
vibration likely to be detected on a seismograph? >>
Hi Ron,
My experience living under planes taking off from busy Orlando, FL airport is
it won't make a bit of difference. During the winter I live in Orlando and
operate a vertical leaf spring seismometer with a 1 Hz low pass filter. Very
little if any cultural noise got through the filter at another location about
40 m from a busy highway with many big trucks. There I could see the highway
noise on an oscilloscope before the filter but none of it got through the 1
Hz low pass filter.
Good luck,
Cap
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Public Seismic Network Mailing List (PSN-L)
Subject: Re: noise from aircraft question
From: Ron Thompson rlthompson@.................
Date: Sun, 30 Sep 2001 21:51:32 -0230
Thanks,
When I get time again, (not likely to happen till spring), I'll see about
getting back to building a detector. We get some rather large aircraft at times,
C5's, and Antonov 124's.
Ron
CapAAVSO@....... wrote:
> In a message dated 9/30/01 9:52:05 PM GMT Daylight Time,
> rlthompson@................. writes:
>
> << The airport is realitively close to the town, and that night the
> departing aircraft were flying over the town. Some of the larger
> aircraft rattle the windows, and shake the house. Is this type of
> vibration likely to be detected on a seismograph? >>
>
> Hi Ron,
>
> My experience living under planes taking off from busy Orlando, FL airport is
> it won't make a bit of difference. During the winter I live in Orlando and
> operate a vertical leaf spring seismometer with a 1 Hz low pass filter. Very
> little if any cultural noise got through the filter at another location about
> 40 m from a busy highway with many big trucks. There I could see the highway
> noise on an oscilloscope before the filter but none of it got through the 1
> Hz low pass filter.
>
> Good luck,
> Cap
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
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Subject: Re: noise from aircraft question
From: ChrisAtUpw@.......
Date: Sun, 30 Sep 2001 21:15:37 EDT
In a message dated 30/09/01, rlthompson@................. writes:
> Late one recent night I realized that building a seismic detector for my
> location may be a waste of time.
> The airport is realitively close to the town, and that night the
> departing aircraft were flying over the town. Some of the larger aircraft
> rattle the windows, and shake the house. Is this type of vibration likely
> to be detected on a seismograph?
Depends a bit where you put your seismometer and what frequencies /
periods you use. Environmental noise tends to be bad from maybe 20 Hz up, but
this should have been filtered out anyway.
The top cut seis filter is maybe 10 Hz for quieter locations, or 3 Hz
for noisier ones. You get the ocean background between 1 and 10 seconds,
maybe peaking in the 6 second region, so if you are looking at 3 Hz down to 1
Hz or below 0.1 Hz, you will probably be OK.
You must not expect the earth to be 'quiet' anyway. Sorting out which
signal is due to which cause is all part of the fun. I have a gale blowing
here at the moment and the background noise is way up. Can't even pick out
the traffic from the main road about 100 yards away, which more usually gives
me problems! With viewing programmes like Winquake, you can do digital
filtering and remove a lot of noise after it has been recorded. The results
can be quite spectacular.
Have you made any progress with the sensor electronics that you were
going to try out, yet? Do keep us informed!
Regards,
Chris Chapman
<HTML><FONT FACE=arial,helvetica><FONT SIZE=2>In a message dated 30/09/01, rlthompson@................. writes:
<BR>
<BR><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">  
; Late one recent night I realized that building a seismic detector for my location may be a waste of time.
<BR> The airport is realitively close to the town, and that night the departing aircraft were flying over the
town. Some of the larger aircraft rattle the windows, and shake the house. Is this type of vibration likely to be detected on
a seismograph? </BLOCKQUOTE>
<BR>
<BR> Depends a bit where you put your seismometer and what frequencies / periods you use. E
nvironmental noise tends to be bad from maybe 20 Hz up, but this should have been filtered out anyway.
<BR>
<BR> The top cut seis filter is maybe 10 Hz for quieter locations, or 3 Hz for noisier ones
. You get the ocean background between 1 and 10 seconds, maybe peaking in the 6 second region, so if you are looking at 3 Hz do
wn to 1 Hz or below 0.1 Hz, you will probably be OK.
<BR>
<BR> You must not expect the earth to be 'quiet' anyway. Sorting out which signal is due to
which cause is all part of the fun. I have a gale blowing here at the moment and the background noise is way up. Can't even pi
ck out the traffic from the main road about 100 yards away, which more usually gives me problems! With viewing programmes like
Winquake, you can do digital filtering and remove a lot of noise after it has been recorded. The results can be quite spectacul
ar.
<BR>
<BR> Have you made any progress with the sensor electronics that you were going to try out,
yet? Do keep us informed!
<BR>
<BR> Regards,
<BR>
<BR> Chris Chapman
<BR></FONT></HTML>
Subject: Re: noise from aircraft question
From: Ron Thompson rlthompson@.................
Date: Mon, 01 Oct 2001 07:24:50 -0230
> No progress yet, but its not due to a lack of interest. I think
> that I'll start with the mechanical components first, then if the
> detector itself doesn't work out I can use a more tried and proven
> design.
As I'm well inland here I don't expect to have much noise from the
sea. But it does get windy and I have trees on the property and a
wooden power line pole near where I hoped to install the detector (on
the concrete floor of a storage shed).
Ron
>
>
> Have you made any progress with the sensor electronics that you
> were going to try out, yet? Do keep us informed!
>
> Regards,
>
> Chris Chapman
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
<blockquote TYPE=CITE><font face="arial,helvetica"><font size=-1>
No progress yet, but its not due to a lack of interest. I think that
I'll start with the mechanical components first, then if the detector itself
doesn't work out I can use a more tried and proven design.</font></font></blockquote>
<p><br> As I'm well inland here I don't expect to have
much noise from the sea. But it does get windy and I have trees on
the property and a wooden power line pole near where I hoped to install
the detector (on the concrete floor of a storage shed).
<p> Ron
<br>
<blockquote TYPE=CITE><font face="arial,helvetica"><font size=-1></font></font>
<p><font face="arial,helvetica"><font size=-1>
Have you made any progress with the sensor electronics that you were going
to try out, yet? Do keep us informed!</font></font>
<p><font face="arial,helvetica"><font size=-1>
Regards,</font></font>
<p><font face="arial,helvetica"><font size=-1>
Chris Chapman</font></font></blockquote>
</html>
Subject: Manuf. Production/Contrl Software For $1,495.00!
From: jbsptrsft55@.........
Date: Tue, 02 Oct 2001 09:00:55 +0100
(ES102)Job Master, a complete, user friendly Windows based software
package, can manage and control your operation from sales quote to
shipment.
For one week only, Job Master, normally $2,495.00, is on sale for a
total price of $1,495.00. In order for you to receive this $1,000.00
savings we must have your order by October 10.
(To reply by E Mail to this message or be removed from our list, Please
go to the bottom of this message for an E Mail link.)
Job Master is designed specifically for small to medium sized
manufacturers, and costs many thousands of dollars less than any other
even remotely comparable software package.
Following is a list of features. If you have any questions, would like
to discuss the package further, or if you would like to obtain our Web
site address for a total walk through of the program, please call me
directly at (661) 254-9926.
By way of background, we are a software company, which for some years
has specialized in the development of custom software, primarily for
small to medium sized manufacturers. Job Master is a distillation of
over a million and a half dollars of software we have developed to
control and manage the production of our manufacturing clients.
Job Master contains the following features:
1. QUOTATION MODULE. In this module, quotes are developed, modified,
and produced for sending to your client. A history is kept of all
quotes for future reference, or modification for other clients. All
quotations and revisions are "auto numbered," including versions. The
quotes section allows for the entry of parts/processes, and costing of
each, including materials, labor, markup, and taxes. Inventory status
can be accessed from this section for reference.
2. SALES ORDER. Once a quotation is accepted, the final quotation
information can be transformed into a Sales Order for your client's
signature on a "point and click" basis. The Sales Order can be
modified and re issued if necessary. A history if kept of all Sales
Orders for future reference, or modification for other clients. All
sales orders and revisions are "auto numbered," including versions.
Inventory status can be accessed from this section for reference.
3. CUSTOMER LETTERS can be created from the Quotation and Sales Order
sections.
4. SHOP TRAVELER/WORK ORDER. Once a Sales Order is accepted, the sales
order information can be transformed into a shop traveler/work order on
a "point and click" basis. Each item on the Sales Order becomes a shop
traveler/work order, with each step of production of the item then
listed on the traveler/work order. Each such traveler/work order is
tied back into the Sales Order. The shop traveler/work order allows
for the entry of line items, and notes on each line item. The shop
traveler/work order contains a "notes" section. The Shop traveler/work
order allows for the storing or attachment of drawings to the
traveler/work order. The shop traveler/work order also contains a
"drop down," from which standard processes can be selected for
inclusion on the shop traveler/work order. The shop traveler/work
order numbers progress in order of production sequence, and re numbers
them if new steps are added. The shop traveler/work order allows for
change orders or revisions, and numbers changes in sequence of the
original shop traveler/work order number; i.e., 100, 100-1, 100-2, etc.
All shop traveler/work orders and related revisions are retained in
memory for future reference. The shop traveler/work order is bar coded
for tracking of production step by step, and production of ongoing
client status reports. Bar coding includes the ability for an employee
to "swipe" their own ID bar code for recording in the system as to who
upgraded what step. The shop traveler/work order function also allows
for manual update of production status. The shop traveler/work order
allows for quality control sign off, and the final production of
certifications, either from a "canned" list, or hand typed in on a case
by case basis.
5. INVENTORY. The application includes an inventory section, which
allows operations to check materials inventory in and out. The
inventory section allows for the comparison of inventory received
against a P.O., and produces an "overage/underage" report of inventory
received as compared against the P.O. The inventory section allows for
the setting of minimum (re-order now!) and maximum inventory amounts,
and produces reports showing what inventory needs to be ordered, as
well as inventory that is at or above the maximum set to have in house.
The inventory section also tracks "partially shipped" orders, which are
tied in to the shipping function. This section shows how much
completed product under a particular order has been actually shipped to
a client, and how much remains to be shipped. The balance is adjusted
as shipments are made.
6. REQUEST FOR PURCHASE. The application allows operators to produce a
Request For Purchase for accounting for any inventory items, which need
to be ordered. Inventory items have a drop down of approved vendors
for each item.
7. REQUEST FOR BID. The application allows operators to produce a
Request For Bid for accounting to send to Vendors for any inventory
items, which need to be ordered. Inventory items have a drop down of
approved vendors for each item to which Requests For Bid can be sent.
8. INVOICE. The application produces an invoice/invoice detail for all
completed items ready to be billed/shipped to clients.
9. PRODUCTION OUTPUT STATUS. The application produces a date range
selectable report on how much product, and the value of the product,
which was completed during a selected date range. The application also
produces a report on how many orders, and the value of those orders,
which remain to be completed during a selected date range.
10. The application produces SHIPPING DOCUMENTS as per selected
shippers, and produces a PACKING SLIP.
11. The application has a "FIND" FUNCTION in selected sections,
allowing for searches by customer name, work order number, etc.
12. The application has "AUTO FILL;" i.e., when an operator starts to
type in a name, number, etc. all related information auto fills after
the first few letters or numbers are typed in.
Job Master is currently being sold in the marketplace for $2,495.00 per
package. However, if we receive your order by October 10.
Again, if you have any questions at all, or would like to place your
order, please call me on my direct line, (661) 254-9926. Thank you!
Mario Chavez
Vice President of Sales and Marketing
Link It Software Corp.
-----------------------------------------------------------------------
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Per Section 301, Paragraph (a)(2)(C) of S. 1618.
To REPLY or be REMOVED from this solicitated email list, please click
on the E Mail address following this message and type "REMOVE" or
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Subject: REMOVE
From: peaches@............ (Donna Whitaker)
Date: Tue, 2 Oct 2001 06:27:27 -1000 (HST)
REMOVE
>
>(ES102)Job Master, a complete, user friendly Windows based software
>package, can manage and control your operation from sales quote to
>shipment.
>
>For one week only, Job Master, normally $2,495.00, is on sale for a
>total price of $1,495.00. In order for you to receive this $1,000.00
>savings we must have your order by October 10.
>
>(To reply by E Mail to this message or be removed from our list, Please
>go to the bottom of this message for an E Mail link.)
>
>Job Master is designed specifically for small to medium sized
>manufacturers, and costs many thousands of dollars less than any other
>even remotely comparable software package.
>
>Following is a list of features. If you have any questions, would like
>to discuss the package further, or if you would like to obtain our Web
>site address for a total walk through of the program, please call me
>directly at (661) 254-9926.
>
>By way of background, we are a software company, which for some years
>has specialized in the development of custom software, primarily for
>small to medium sized manufacturers. Job Master is a distillation of
>over a million and a half dollars of software we have developed to
>control and manage the production of our manufacturing clients.
>
>Job Master contains the following features:
>
>1. QUOTATION MODULE. In this module, quotes are developed, modified,
>and produced for sending to your client. A history is kept of all
>quotes for future reference, or modification for other clients. All
>quotations and revisions are "auto numbered," including versions. The
>quotes section allows for the entry of parts/processes, and costing of
>each, including materials, labor, markup, and taxes. Inventory status
>can be accessed from this section for reference.
>
>2. SALES ORDER. Once a quotation is accepted, the final quotation
>information can be transformed into a Sales Order for your client's
>signature on a "point and click" basis. The Sales Order can be
>modified and re issued if necessary. A history if kept of all Sales
>Orders for future reference, or modification for other clients. All
>sales orders and revisions are "auto numbered," including versions.
>Inventory status can be accessed from this section for reference.
>
>3. CUSTOMER LETTERS can be created from the Quotation and Sales Order
>sections.
>
>4. SHOP TRAVELER/WORK ORDER. Once a Sales Order is accepted, the sales
>order information can be transformed into a shop traveler/work order on
>a "point and click" basis. Each item on the Sales Order becomes a shop
>traveler/work order, with each step of production of the item then
>listed on the traveler/work order. Each such traveler/work order is
>tied back into the Sales Order. The shop traveler/work order allows
>for the entry of line items, and notes on each line item. The shop
>traveler/work order contains a "notes" section. The Shop traveler/work
>order allows for the storing or attachment of drawings to the
>traveler/work order. The shop traveler/work order also contains a
>"drop down," from which standard processes can be selected for
>inclusion on the shop traveler/work order. The shop traveler/work
>order numbers progress in order of production sequence, and re numbers
>them if new steps are added. The shop traveler/work order allows for
>change orders or revisions, and numbers changes in sequence of the
>original shop traveler/work order number; i.e., 100, 100-1, 100-2, etc.
>All shop traveler/work orders and related revisions are retained in
>memory for future reference. The shop traveler/work order is bar coded
>for tracking of production step by step, and production of ongoing
>client status reports. Bar coding includes the ability for an employee
>to "swipe" their own ID bar code for recording in the system as to who
>upgraded what step. The shop traveler/work order function also allows
>for manual update of production status. The shop traveler/work order
>allows for quality control sign off, and the final production of
>certifications, either from a "canned" list, or hand typed in on a case
>by case basis.
>
>5. INVENTORY. The application includes an inventory section, which
>allows operations to check materials inventory in and out. The
>inventory section allows for the comparison of inventory received
>against a P.O., and produces an "overage/underage" report of inventory
>received as compared against the P.O. The inventory section allows for
>the setting of minimum (re-order now!) and maximum inventory amounts,
>and produces reports showing what inventory needs to be ordered, as
>well as inventory that is at or above the maximum set to have in house.
>The inventory section also tracks "partially shipped" orders, which are
>tied in to the shipping function. This section shows how much
>completed product under a particular order has been actually shipped to
>a client, and how much remains to be shipped. The balance is adjusted
>as shipments are made.
>
>6. REQUEST FOR PURCHASE. The application allows operators to produce a
>Request For Purchase for accounting for any inventory items, which need
>to be ordered. Inventory items have a drop down of approved vendors
>for each item.
>
>7. REQUEST FOR BID. The application allows operators to produce a
>Request For Bid for accounting to send to Vendors for any inventory
>items, which need to be ordered. Inventory items have a drop down of
>approved vendors for each item to which Requests For Bid can be sent.
>
>8. INVOICE. The application produces an invoice/invoice detail for all
>completed items ready to be billed/shipped to clients.
>
>9. PRODUCTION OUTPUT STATUS. The application produces a date range
>selectable report on how much product, and the value of the product,
>which was completed during a selected date range. The application also
>produces a report on how many orders, and the value of those orders,
>which remain to be completed during a selected date range.
>
>10. The application produces SHIPPING DOCUMENTS as per selected
>shippers, and produces a PACKING SLIP.
>
>11. The application has a "FIND" FUNCTION in selected sections,
>allowing for searches by customer name, work order number, etc.
>
>12. The application has "AUTO FILL;" i.e., when an operator starts to
>type in a name, number, etc. all related information auto fills after
>the first few letters or numbers are typed in.
>
>Job Master is currently being sold in the marketplace for $2,495.00 per
>package. However, if we receive your order by October 10.
>
>Again, if you have any questions at all, or would like to place your
>order, please call me on my direct line, (661) 254-9926. Thank you!
>
>
>Mario Chavez
>Vice President of Sales and Marketing
>Link It Software Corp.
>
>
>
>-----------------------------------------------------------------------
>-------------------
>
>
>This message is sent in compliance of the new e-mail bill: SECTION 301.
>Per Section 301, Paragraph (a)(2)(C) of S. 1618.
>
>To REPLY or be REMOVED from this solicitated email list, please click
>on the E Mail address following this message and type "REMOVE" or
>"REPLY" in the subject line: jbsptrsft55@.........
>-----------------------------------------------------------------------
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>
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>unsubscribe psn-l (first line only). You will also need to email:
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>unsubscribe
>
>
>
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Subject: What type of foundation is needed
From: "Jan D. Marshall" jandmarshall@............
Date: Tue, 2 Oct 2001 12:12:37 -0600
I am starting to design my sensors and electronics and have decided that =
I understand the requirments there pretty well -- what I don't have a =
very good understanding on is what do I need for a base or foundation to =
set the sensors on. What type of mass does it need? does it need to set =
on bed rock? I do not have any cement slab floors.
Thanks
Jan D. Marshall
Nampa, Idaho
jandmarshall@............
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 5.50.4807.2300" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>I am starting to design my sensors and =
electronics=20
and have decided that I understand the requirments there pretty well -- =
what I=20
don't have a very good understanding on is what do I need for a base or=20
foundation to set the sensors on. What type of mass does it need? =
does it=20
need to set on bed rock? I do not have any cement slab=20
floors.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Thanks</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV>Jan D. Marshall<BR>Nampa, Idaho<BR><A=20
href=3D"mailto:jandmarshall@............">jandmarshall@............</A><B=
R></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"><FONT=20
face=3DArial size=3D2></FONT> </BLOCKQUOTE></BODY></HTML>
Subject: FW: Stephenson Probe - website upgrade
From: steve hammond shammon1@.............
Date: Wed, 3 Oct 2001 15:01:18 -0700
I received this from Bill Stephenson and thought I would pass it on to the group.
Regards, Steve Hammond
Subject: Stephenson Probe - website upgrade
Hi,
This is just to alert you to the fact that new information has been put on the
website describing the probe.
Cheers,
Bill
--
Bill Stephenson, Seismology Section,
Hazards Group, Institute of Geological & Nuclear Sciences,
P.O. Box 30368, Lower Hutt, New Zealand
Phone: +64 4 570 1444 Direct: +64 4 570 4757 Fax: +64 4 570 1440
B.Stephenson@..........
The Stephenson Probe: http://www.gns.cri.nz/earthact/probe
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Stephenson Probe - website upgrade
From: "valhutch" valhutch@.........
Date: Wed, 3 Oct 2001 17:34:28 -0600
Please erase me from your lists of emails.
valhutch@.........
-----Original Message-----
From: steve hammond <shammon1@.............>
To: psn-l@.............. <psn-l@..............>
Date: Miércoles, Octubre 03, 2001 03:56 PM
Subject: FW: Stephenson Probe - website upgrade
>
>I received this from Bill Stephenson and thought I would pass it on to the
group.
>Regards, Steve Hammond
>
>
>Subject: Stephenson Probe - website upgrade
>
>
>
>Hi,
>
>This is just to alert you to the fact that new information has been put on
the
>website describing the probe.
>
>Cheers,
>Bill
>--
>Bill Stephenson, Seismology Section,
>Hazards Group, Institute of Geological & Nuclear Sciences,
>P.O. Box 30368, Lower Hutt, New Zealand
>Phone: +64 4 570 1444 Direct: +64 4 570 4757 Fax: +64 4 570 1440
>B.Stephenson@..........
>
>The Stephenson Probe: http://www.gns.cri.nz/earthact/probe
>
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
>To leave this list email PSN-L-REQUEST@.............. with
>the body of the message (first line only): unsubscribe
>See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: This is a test
From: "Larry Cochrane" cochrane@..........
Date: Wed, 3 Oct 2001 17:16:30 -0700
Sorry, this is a test.
-Larry Cochrane
-------------
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Subject: What type of foundation
From: "Jan D. Marshall" jandmarshall@............
Date: Thu, 4 Oct 2001 20:52:09 -0600
I am starting to design my sensors and electronics and have decided that =
I understand the requirments there pretty well -- what I don't have a =
very good understanding on is what do I need for a base or foundation to =
set the sensors on. What type of mass does it need? does it need to set =
on bedrock? I do not have any cement slab floors.
Thanks
Jan D. Marshall
Nampa, Idaho
jandmarshall@............
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
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<DIV><FONT face=3DArial size=3D2>
<DIV><FONT face=3DArial size=3D2>I am starting to design my sensors and =
electronics=20
and have decided that I understand the requirments there pretty well -- =
what I=20
don't have a very good understanding on is what do I need for a base or=20
foundation to set the sensors on. What type of mass does it need? =
does it=20
need to set on bedrock? I do not have any cement slab =
floors.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Thanks</FONT></DIV>
<DIV> </DIV></FONT></DIV>
<DIV>Jan D. Marshall<BR>Nampa, Idaho<BR><A=20
href=3D"mailto:jandmarshall@............">jandmarshall@............</A><B=
R></DIV>
<BLOCKQUOTE=20
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Subject: Re: What type of foundation
From: "meredith lamb" mlamb1@.........
Date: Thu, 04 Oct 2001 23:41:10 -0700
Hi Jan,
Perhaps.....the most important aspect is,....what kind of
terrain and/or space do you have available....i.e, city/country,
to place any seismo on. Any house crawlspace available, or
garage, shed, or least disturbed area of land around? One
will have to make "do" with what they have for placement.
If you do indeed have bedrock, that would be a plus....if...its
convenient and adaptable for a seismic "vault". If you have
loose soil, the best remote and least watered/susceptible
area would be best.
The best material seems to be a "pier" of concrete, that can
be inside/outside weather enclosed and somewhat isolated from
domestic seismic sources of "noise"......or....if not possible
to do so, one would have to live with the noise it generates;
which is usually easy to denote with time/experience. The
pier usually needs to "fit" the area required by the sensor/s
anticipated. The thickness of the concrete slab can be
debated I suppose, but I'd try for whatever depth/thickness
you can squeeze in the spot you chose. I use about a 7-8"
thickness of my three piers....which are in reality cast concrete
pavers stacked together but layered in the joints and surfaces
with real concrete. I chose this as it was near impossible to
mix massive concrete on my knees under the house, let alone
move all the sand/concrete therein. For myself, I elected to
also use thick mylar sheet under the piers, to limit water
absorbion into the piers. I even used a water repellent paint
on the pier/s to limit water absorbtion. Even after completion,
you can expect a period of time before the piers stabilize from
curing....perhaps acouple months. If you can make the pier
thickness even greater than say...6 inches thick, I'd do so. Do
not use iron, steel in the pier.
Personally I live in Denver, and in a city lot.....so, I use my
house soil crawlspace for pier/seismometer placements. I
also enclosed the piers with walls and insulation to somewhat
limit temperature excursion that do occur. Among the PSN
members....we kind of all utilize whats available.....
So....in a way....everything gets back to what space you
have now that could be utilized. Next, the physical size of
your anticipated seismos you're planning on building/using.
I think you're right to get into the seismo housing/piers aspect
right off the bat.....if one doesn't; than they will get into alot of
soil tilt, water, weather, temperature related problems that will
make any consistent seismic monitoring rather useless otherwise.
Suggest that any pier/containment is well built and temperature
insulated; this can take time, but it would pay off in the long
run.
Outside of the above,.....what kind of seismic sensors are you
planning on using.....the instrumentation sensor aspect is always
interesting.
Take care, Meredith Lamb
"Jan D. Marshall" wrote:
> I am starting to design my sensors and electronics and have decided
> that I understand the requirments there pretty well -- what I don't
> have a very good understanding on is what do I need for a base or
> foundation to set the sensors on. What type of mass does it need?
> does it need to set on bedrock? I do not have any cement slab floors.
> Thanks Jan D. Marshall
> Nampa, Idaho
> jandmarshall@............
>
>
>
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
<body bgcolor="#FFFFFF">
Hi Jan,
<p>Perhaps.....the most important aspect is,....what kind of
<br>terrain and/or space do you have available....i.e, city/country,
<br>to place any seismo on. Any house crawlspace available, or
<br>garage, shed, or least disturbed area of land around? One
<br>will have to make "do" with what they have for placement.
<br>If you do indeed have bedrock, that would be a plus....if...its
<br>convenient and adaptable for a seismic "vault". If you have
<br>loose soil, the best remote and least watered/susceptible
<br>area would be best.
<p>The best material seems to be a "pier" of concrete, that can
<br>be inside/outside weather enclosed and somewhat isolated from
<br>domestic seismic sources of "noise"......or....if not possible
<br>to do so, one would have to live with the noise it generates;
<br>which is usually easy to denote with time/experience. The
<br>pier usually needs to "fit" the area required by the sensor/s
<br>anticipated. The thickness of the concrete slab can be
<br>debated I suppose, but I'd try for whatever depth/thickness
<br>you can squeeze in the spot you chose. I use about a 7-8"
<br>thickness of my three piers....which are in reality cast concrete
<br>pavers stacked together but layered in the joints and surfaces
<br>with real concrete. I chose this as it was near impossible to
<br>mix massive concrete on my knees under the house, let alone
<br>move all the sand/concrete therein. For myself, I elected to
<br>also use thick mylar sheet under the piers, to limit water
<br>absorbion into the piers. I even used a water repellent paint
<br>on the pier/s to limit water absorbtion. Even after completion,
<br>you can expect a period of time before the piers stabilize from
<br>curing....perhaps acouple months. If you can make the pier
<br>thickness even greater than say...6 inches thick, I'd do so.
Do
<br>not use iron, steel in the pier.
<p>Personally I live in Denver, and in a city lot.....so, I use my
<br>house soil crawlspace for pier/seismometer placements. I
<br>also enclosed the piers with walls and insulation to somewhat
<br>limit temperature excursion that do occur. Among the PSN
<br>members....we kind of all utilize whats available.....
<p>So....in a way....everything gets back to what space you
<br>have now that could be utilized. Next, the physical size of
<br>your anticipated seismos you're planning on building/using.
<p>I think you're right to get into the seismo housing/piers aspect
<br>right off the bat.....if one doesn't; than they will get into alot
of
<br>soil tilt, water, weather, temperature related problems that
will
<br>make any consistent seismic monitoring rather useless otherwise.
<br>Suggest that any pier/containment is well built and temperature
<br>insulated; this can take time, but it would pay off in the long
<br>run.
<p>Outside of the above,.....what kind of seismic sensors are you
<br>planning on using.....the instrumentation sensor aspect is always
<br>interesting.
<p>Take care, Meredith Lamb
<p>"Jan D. Marshall" wrote:
<blockquote TYPE=CITE><style></style>
<font face="Arial"><font size=-1>I
am starting to design my sensors and electronics and have decided that
I understand the requirments there pretty well -- what I don't have a very
good understanding on is what do I need for a base or foundation to set
the sensors on. What type of mass does it need? does it need to set
on bedrock? I do not have any cement slab floors.</font></font> <font face="Arial"><font size=-1>Thanks</font></font>
Jan D. Marshall
<br>Nampa, Idaho
<br><a href="mailto:jandmarshall@............">jandmarshall@............</a>
<blockquote
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> </bloc
kquote>
</blockquote>
</body>
</html>
Subject: Re: What type of foundation
From: "Jan D. Marshall" jandmarshall@............
Date: Fri, 5 Oct 2001 18:12:07 -0600
My first attempt is going to be a Lehman. I am not afraid to tackle =
anything however. As soon as I get an amp, filter, A/D converter and =
the PC software going I thing it is going to be fun expermiting with =
different sensors.
Jan D. Marshall
Nampa, Idaho
jandmarshall@............
----- Original Message -----=20
From: meredith lamb=20
To: psn-l@.................
Sent: Friday, October 05, 2001 12:41 AM
Subject: Re: What type of foundation
Hi Jan,=20
Perhaps.....the most important aspect is,....what kind of=20
terrain and/or space do you have available....i.e, city/country,=20
to place any seismo on. Any house crawlspace available, or=20
garage, shed, or least disturbed area of land around? One=20
will have to make "do" with what they have for placement.=20
If you do indeed have bedrock, that would be a plus....if...its=20
convenient and adaptable for a seismic "vault". If you have=20
loose soil, the best remote and least watered/susceptible=20
area would be best.=20
The best material seems to be a "pier" of concrete, that can=20
be inside/outside weather enclosed and somewhat isolated from=20
domestic seismic sources of "noise"......or....if not possible=20
to do so, one would have to live with the noise it generates;=20
which is usually easy to denote with time/experience. The=20
pier usually needs to "fit" the area required by the sensor/s=20
anticipated. The thickness of the concrete slab can be=20
debated I suppose, but I'd try for whatever depth/thickness=20
you can squeeze in the spot you chose. I use about a 7-8"=20
thickness of my three piers....which are in reality cast concrete=20
pavers stacked together but layered in the joints and surfaces=20
with real concrete. I chose this as it was near impossible to=20
mix massive concrete on my knees under the house, let alone=20
move all the sand/concrete therein. For myself, I elected to=20
also use thick mylar sheet under the piers, to limit water=20
absorbion into the piers. I even used a water repellent paint=20
on the pier/s to limit water absorbtion. Even after completion,=20
you can expect a period of time before the piers stabilize from=20
curing....perhaps acouple months. If you can make the pier=20
thickness even greater than say...6 inches thick, I'd do so. Do=20
not use iron, steel in the pier.=20
Personally I live in Denver, and in a city lot.....so, I use my=20
house soil crawlspace for pier/seismometer placements. I=20
also enclosed the piers with walls and insulation to somewhat=20
limit temperature excursion that do occur. Among the PSN=20
members....we kind of all utilize whats available.....=20
So....in a way....everything gets back to what space you=20
have now that could be utilized. Next, the physical size of=20
your anticipated seismos you're planning on building/using.=20
I think you're right to get into the seismo housing/piers aspect=20
right off the bat.....if one doesn't; than they will get into alot of=20
soil tilt, water, weather, temperature related problems that will=20
make any consistent seismic monitoring rather useless otherwise.=20
Suggest that any pier/containment is well built and temperature=20
insulated; this can take time, but it would pay off in the long=20
run.=20
Outside of the above,.....what kind of seismic sensors are you=20
planning on using.....the instrumentation sensor aspect is always=20
interesting.=20
Take care, Meredith Lamb=20
"Jan D. Marshall" wrote:=20
I am starting to design my sensors and electronics and have decided =
that I understand the requirments there pretty well -- what I don't have =
a very good understanding on is what do I need for a base or foundation =
to set the sensors on. What type of mass does it need? does it need to =
set on bedrock? I do not have any cement slab floors. Thanks Jan D. =
Marshall=20
Nampa, Idaho=20
jandmarshall@...............
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 5.50.4807.2300" name=3DGENERATOR></HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>My first attempt is going to be a =
Lehman. I=20
am not afraid to tackle anything however. As soon as I get an amp, =
filter,=20
A/D converter and the PC software going I thing it is going to be fun=20
expermiting with different sensors.</FONT></DIV>
<DIV> </DIV>
<DIV>Jan D. Marshall<BR>Nampa, Idaho<BR><A=20
href=3D"mailto:jandmarshall@............">jandmarshall@............</A><B=
R></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A title=3Dmlamb1@......... href=3D"mailto:mlamb1@.........">meredith =
lamb</A>=20
</DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dpsn-l@.................
href=3D"mailto:psn-l@..............">psn-l@..............</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Friday, October 05, 2001 =
12:41=20
AM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: What type of=20
foundation</DIV>
<DIV><BR></DIV>Hi Jan,=20
<P>Perhaps.....the most important aspect is,....what kind of =
<BR>terrain=20
and/or space do you have available....i.e, city/country, <BR>to place =
any=20
seismo on. Any house crawlspace available, or <BR>garage, shed, =
or least=20
disturbed area of land around? One <BR>will have to make "do" =
with what=20
they have for placement. <BR>If you do indeed have bedrock, that would =
be a=20
plus....if...its <BR>convenient and adaptable for a seismic =
"vault". If=20
you have <BR>loose soil, the best remote and least watered/susceptible =
<BR>area would be best.=20
<P>The best material seems to be a "pier" of concrete, that can <BR>be =
inside/outside weather enclosed and somewhat isolated from =
<BR>domestic=20
seismic sources of "noise"......or....if not possible <BR>to do so, =
one would=20
have to live with the noise it generates; <BR>which is usually easy to =
denote=20
with time/experience. The <BR>pier usually needs to "fit" the =
area=20
required by the sensor/s <BR>anticipated. The thickness of the =
concrete=20
slab can be <BR>debated I suppose, but I'd try for whatever =
depth/thickness=20
<BR>you can squeeze in the spot you chose. I use about a 7-8"=20
<BR>thickness of my three piers....which are in reality cast concrete=20
<BR>pavers stacked together but layered in the joints and surfaces =
<BR>with=20
real concrete. I chose this as it was near impossible to <BR>mix =
massive=20
concrete on my knees under the house, let alone <BR>move all the =
sand/concrete=20
therein. For myself, I elected to <BR>also use thick mylar sheet =
under=20
the piers, to limit water <BR>absorbion into the piers. I even =
used a=20
water repellent paint <BR>on the pier/s to limit water =
absorbtion. Even=20
after completion, <BR>you can expect a period of time before the piers =
stabilize from <BR>curing....perhaps acouple months. If you can =
make the=20
pier <BR>thickness even greater than say...6 inches thick, I'd do =
so. Do=20
<BR>not use iron, steel in the pier.=20
<P>Personally I live in Denver, and in a city lot.....so, I use my =
<BR>house=20
soil crawlspace for pier/seismometer placements. I <BR>also =
enclosed the=20
piers with walls and insulation to somewhat <BR>limit temperature =
excursion=20
that do occur. Among the PSN <BR>members....we kind of all =
utilize whats=20
available.....=20
<P>So....in a way....everything gets back to what space you <BR>have =
now that=20
could be utilized. Next, the physical size of <BR>your =
anticipated=20
seismos you're planning on building/using.=20
<P>I think you're right to get into the seismo housing/piers aspect =
<BR>right=20
off the bat.....if one doesn't; than they will get into alot of =
<BR>soil tilt,=20
water, weather, temperature related problems that will <BR>make =
any=20
consistent seismic monitoring rather useless otherwise. <BR>Suggest =
that any=20
pier/containment is well built and temperature <BR>insulated; this can =
take=20
time, but it would pay off in the long <BR>run.=20
<P>Outside of the above,.....what kind of seismic sensors are you =
<BR>planning=20
on using.....the instrumentation sensor aspect is always =
<BR>interesting.=20
<P>Take care, Meredith Lamb=20
<P>"Jan D. Marshall" wrote:=20
<BLOCKQUOTE TYPE=3D"CITE">
<STYLE></STYLE>
<FONT face=3DArial><FONT size=3D-1>I am starting to design my =
sensors and=20
electronics and have decided that I understand the requirments there =
pretty=20
well -- what I don't have a very good understanding on is what do I =
need for=20
a base or foundation to set the sensors on. What type of mass =
does it=20
need? does it need to set on bedrock? I do not have any cement =
slab=20
floors.</FONT></FONT> <FONT face=3DArial><FONT =
size=3D-1>Thanks</FONT></FONT>=20
Jan D. Marshall <BR>Nampa, Idaho <BR><A=20
=
href=3D"mailto:jandmarshall@............">jandmarshall@............</A>=20
<BLOCKQUOTE=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: =
0px"> </BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>
Subject: Pendulum Periods
From: "Jan D. Marshall" jandmarshall@............
Date: Fri, 5 Oct 2001 21:53:40 -0600
Could some one give me a quick 101 course on what is ment by the
"period of the pendulum" how does that relate to a seismograph,
what period are we striving for?
Jan D. Marshall
Nampa, Idaho
jandmarshall@............
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Pendulum Periods
From: Karl Cunningham karlc@..........
Date: Sun, 07 Oct 2001 12:32:30 -0700
Hi Jan --
I'll take a stab at it... I don't know anything about your level of
knowledge of math and physics, and the following may be too elementary or
too complex, but please let me know if you want more explanation.
Take a string about 3 feet long and tie a weight at one end (a shoe would
work). Hold the string by the other end and let the weight dangle down
without hitting anything. Then have someone pull the weight a bit to the
side (keeping the string taut) and let it go. It will swing back an forth,
and the time it takes it to go from one end over and back to the same place
again is the period.
The period of a simple pendulum (one with only one weight on it and a
string that weighs little compared to the weight, is given by the following
equation:
T = 2 * pi * sqrt(L / G)
The variables are: T is time in seconds, pi is the constant 3.14159... ,
sqrt is an abreviation for square root, L is the length of the string from
the pivot to the center of mass of the weight, and G is the acceleration of
gravity. If L is expressed in inches, the acceleration of gravity should
be 386.1 inches per second squared. You really don't need to worry about
the units if you use the length in inches, and use 386.1 for gravity.
For example, use a length of 30 inches. Take 30 and divide it by 386.1 to
get 0.0777. Take the square root of that to get 0.2787. Then multiply the
result by 3.14159 and result of that by 2, to get 1.751 second. So a 30"
long pendulum will take about 1.75 seconds to swing over and back to the
same place. That is its period.
When making a seismometer the longer the period of the pendulum the longer
the period of the waves that can be measured. Usually, this is desireable.
Regards,
Karl Cunningham
--On Friday, October 05, 2001 21:53 -0600 "Jan D. Marshall"
<jandmarshall@............> wrote:
> Could some one give me a quick 101 course on what is ment by the
> "period of the pendulum" how does that relate to a seismograph,
> what period are we striving for?
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: ADXL202
From: "Larry Cochrane" cochrane@..............
Date: Sun, 7 Oct 2001 15:11:05 -0700
Hi Angel,
The new chips are based on the same technology as the original ADX05 sensor.
These devices are too noisy for general seismology. Since their dynamic
range is pretty poor they could only be used as a very strong motion sensor.
I am looking into making a sensor based on another type of accelerometer
chip made by Measurement Specialties Inc. Here is a link to the sensor
http://www.msiusa.com/icsensors/catalog/data/accel/M_3052.pdf. I currently
have one on-line, the sensor ID is *.lctsn.psn. So far I have recorded two
small events with the new sensor. The first was a Md2.5. Here's a link to
the PSN file: ftp://ftp.seismicnet.com/quakes/0110/011002.0057.lctsn.psn.
The second event was a Ml3.1 both where 34km from me. The sensor recorded
the second event very nicely. Here's a link to the PSN file:
ftp://ftp.seismicnet.com/quakes/0110/011006.0215.lctsn.psn. I currently have
the gain between the sensor and the A/D board set to +- 0.1 g max. By having
two outputs per axis one could have a strong motion (+- 2.0 g ) channel
with and a high gain channel for monitoring smaller events.
The problem is the cost of the sensor chip is rather high at $195.00 each.
The price goes down to $114.00 in quantities of 25. Digi-Key is now selling
them, but they are out of stock because I just purchased the last 8 devices
they had in-stock.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "angel@volcanbaru" <angel@..............>
To: "Larry Cochrane" <cochrane@..............>
Sent: Sunday, October 07, 2001 4:18 AM
Subject: ADXL202
> Hello Larry,
>
> I can't post to the list when I travel because my isp in Panama will
> relay and the list does not accept mail from this email address.
>
> Has there been any revisiting of using some of Analog Devices new
> chips. Check out this page
>
> http://www.edtn.com/embapps/emba065.htm
>
> I am now in my "vacation" time and only check mail now and then.
>
>
> Best regards,
> angel
>
>
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: New WinQuake beta release
From: "Larry Cochrane" cochrane@..............
Date: Sun, 7 Oct 2001 18:54:22 -0700
All,
I just released a new version of WinQuake. The new beta is version 2.8.2
with a release date of 10/06/01. This release fixes several bugs around the
report handling feature of WQ.
There is still one problem with WQ that I have not been able to fix. This is
the location map printing problem.
You can download the release here: http://www.seismicnet.com/software.html.
Regards,
Larry Cochrane
Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Received Shipment
From: Jim ODonnell jimo17@........
Date: Sun, 7 Oct 2001 21:25:28 -0700
Hi Larry- I got the last of my order on Thursday and all looks good. The
new Filt/amp bords with their 15V PS is nice.
Thanks........Jim
________________________________________________________________
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__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Information Needed
From: CapAAVSO@.......
Date: Thu, 11 Oct 2001 09:42:44 EDT
Hi All,
Can someone please tell me the name of the hardware company Sean - Thomas
often recommended as a source of materials to build seismometers?
Thanks,
Cap
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Information Needed
From: Doug Crice dcrice@............
Date: Thu, 11 Oct 2001 06:49:56 -0700
McMaster-Carr, web site http://www.mcmaster.com
But if you can get one of their 3-inch catalogs, it's hours of great
browsing.
CapAAVSO@....... wrote:
>
> Hi All,
>
> Can someone please tell me the name of the hardware company Sean - Thomas
> often recommended as a source of materials to build seismometers?
>
> Thanks,
> Cap
> __________________________________________________________
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Information Needed
From: CapAAVSO@.......
Date: Thu, 11 Oct 2001 11:51:30 EDT
In a message dated 10/11/01 2:50:31 PM GMT Daylight Time, dcrice@............
writes:
<< McMaster-Carr, web site http://www.mcmaster.com
But if you can get one of their 3-inch catalogs, it's hours of great
browsing. >>
Thanks Doug,
They are the only company I know that sells Alnico 8 magnets. I just placed
an order for some magnets for the torsion balance magnetometer I'm building.
Alnico 8 is the best because it has the least sensitivity to temperature
changes. Torsion balance magnetometers tend to drift with temperature changes
and this is kept to a minimum by using Alnico 8 magnets.
Thanks again'
Cap
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: my mail
From: "Bryan&Regina Goss" bgoss@..................
Date: Tue, 23 Oct 2001 05:16:44 -0500
Just a test havent heard anything in a while
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<BODY bgColor=3D#ffffff><FONT face=3DArial size=3D2>Just a test havent =
heard anything=20
in a while</FONT></BODY></HTML>
Subject: UNSUBSCRIBE
From: Mike Lozano mikel@...............
Date: Tue, 23 Oct 2001 21:35:21 -0500
UNSUBSCRI BE
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: PSN mailing list
From: "Larry Cochrane" cochrane@..............
Date: Mon, 29 Oct 2001 15:54:30 -0800
Rick,
There haven't been any post to the list in the past few days. You should see
this message coming from the PSN-L list and from me directly.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "Richard Phillips" <raphillips5@........>
To: <cochrane@..............>
Sent: Monday, October 29, 2001 3:46 PM
Subject: PSN mailing list
> Dear Larry,
>
> please make sure that I am still on PSN mailing list. I have not
> received any e-mail for several days.
>
> Thanks,
>
> Rick Phillips
>
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: PSN mailing list
From: johnc c cole johnccole1@........
Date: Mon, 29 Oct 2001 18:44:29 -0600
Larry, I was also worried about the inactivity on PSN . This note is to
let everyone know that I am also alive and well . John C Cole, Pearland,
Texas
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Subject: Re: PSN mailing list
From: ChrisAtUpw@.......
Date: Mon, 29 Oct 2001 21:14:35 EST
John Cole talking of his good health reminds me that it might be a
good moment to ask how Sean Thomas Morrissey is recovering? Wish him well
anyway.
Regards,
Chris Chapman
<HTML><FONT FACE=arial,helvetica><FONT SIZE=2> John Cole talking of his good health reminds me
that it might be a good moment to ask how Sean Thomas Morrissey is recovering? Wish him well anyway.
<BR>
<BR> Regards,
<BR>
<BR> Chris Chapman </FONT></HTML>
Subject: close event
From: ian ian@...........
Date: Mon, 29 Oct 2001 16:35:32 -1000
I've just been "rocked" by a 3.1 1.5 miles from my sensor. I didn't
feel anything and the trace superficially looks like surface noise.
I've uploaded the event, 011029.1942.hl0.psn. I'm puzzled by such a
close event of moderate strength going by so un-noticed.
I Smith
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: close event
From: "Larry Cochrane" cochrane@..............
Date: Mon, 29 Oct 2001 19:51:54 -0800
I too had a close event the other day. The event was a MD2.2 right here in
Redwood City. The non felt event was ~ 4km or ~2 miles from me. I think this
is the closes event I have ever recorded. I was lucky to record it on all of
my sensors. I just got done with rearranging my station. The even happened
only 15 minutes after I got my system back on line.
Recently I added a second channel based on the IDS3052 accelerometer chip.
This channel is oriented vertically and it recorded the event very nicely.
The event file is 011027.0618.lctsz.psn.
Here's an update on the new accelerometer sensor board based on the IDS3052
chip. I hope to be selling it soon. I completed the PC board layout last
week. I should be getting 10 PC boards in a few days. Once I verify that the
board works, I will be sending out a email message to the list as well as
make a web page documenting the new product.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "ian" <ian@...........>
To: <psn-l@..............>
Sent: Monday, October 29, 2001 6:35 PM
Subject: close event
> I've just been "rocked" by a 3.1 1.5 miles from my sensor. I didn't
> feel anything and the trace superficially looks like surface noise.
>
> I've uploaded the event, 011029.1942.hl0.psn. I'm puzzled by such a
> close event of moderate strength going by so un-noticed.
>
> I Smith
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
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Public Seismic Network Mailing List (PSN-L)
Subject: lines
From: "JORD" jord@............
Date: Tue, 30 Oct 2001 23:30:46 -0500
Can high voltage power lines have an effect on how my sensor works?
The lines are about 250-300 feet away.
Whitby Ontario now .=20
Formaly from Toronto.
Thank You
Randy.......................
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<DIV><FONT face=3DArial size=3D2>Can high voltage power lines have an =
effect on how=20
my sensor works?</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>The lines are about 250-300 feet =
away.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Whitby Ontario now . </FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Formaly from Toronto.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Thank You</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial =
size=3D2>Randy.......................</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
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Subject: Re: lines
From: "Erich Kern" efkern@.............
Date: Tue, 30 Oct 2001 20:40:32 -0800
Randy,
Not likely to affect the sensor directly, but the broadband RF interference that those
lines radiate could get into the electronics if your signal lines are not shielded.
What are you observing that might be interference?
Regards,
Erich
----- Original Message -----
From: "JORD" <jord@............>
To: <psn-l@..............>
Sent: Tuesday, October 30, 2001 8:30 PM
Subject: lines
Can high voltage power lines have an effect on how my sensor works?
The lines are about 250-300 feet away.
Whitby Ontario now .
Formaly from Toronto.
Thank You
Randy.......................
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: lines
From: ChrisAtUpw@.......
Date: Wed, 31 Oct 2001 20:25:54 EST
In a message dated 31/10/01, jord@............ writes:
> Can high voltage power lines have an effect on how my sensor works?
> The lines are about 250-300 feet away.
>
Dear Randy,
If you tell us what type of sensor you are using and something about
your setup, where the sensor is, how long the cables are, the size of the
power line towers, your observations of the effects, etc., we may be able to
help. The short answer is that interference is possible. There are two
types:- electrical / RF interference / switching transients and wind sway on
the electricity pylons. However, you can also get wind generated effects on a
house and from nearby trees. I put a wind speed sensor outside and was able
to clearly identify wind effects on my very solidly built old house.
Regards,
Chris Chapman
<HTML><FONT FACE=arial,helvetica><FONT SIZE=2>In a message dated 31/10/01, jord@............ writes:
<BR>
<BR><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Can hi
gh voltage power lines have an effect on how my sensor works?
<BR>The lines are about 250-300 feet away.
<BR> Randy.</BLOCKQUOTE>
<BR>
<BR>Dear Randy,
<BR>
<BR> If you tell us what type of sensor you are using and something about your setup, where
the sensor is, how long the cables are, the size of the power line towers, your observations of the effects, etc., we may be a
ble to help. The short answer is that interference is possible. There are two types:- electrical / RF interference / switching
transients and wind sway on the electricity pylons. However, you can also get wind generated effects on a house and from nearby
trees. I put a wind speed sensor outside and was able to clearly identify wind effects on my very solidly built old house. &nb
sp;
<BR>
<BR> Regards,
<BR>
<BR> Chris Chapman</FONT></HTML>
Subject: Fw: Quake Warnings Before the Shaking Starts
From: "Larry Cochrane" cochrane@..............
Date: Sun, 4 Nov 2001 12:53:00 -0800
From Jim O'Donnell. -Larry
----- Original Message -----
From: Jim ODonnell
To: cochrane@..............
Sent: Sunday, November 04, 2001 11:28 AM
Subject: Quake Warnings Before the Shaking Starts
Larry- Could you post this for the group.... You should get some hits from
this article.
It is a Shaky Business, but you guys are looking good!...Jim
Quake Warnings Before the Shaking Starts
Early-warning systems for people in earthquake zones are growing closer to
real time
The ham seismology community has an important place in this picture, too.
The Public Seismic Network (PSN) is the longtime home of this ingenious
group of amateurs. Maybe you could visit and bookmark the PSN Web site at
http://psn.quake.net/.
See: http://geology.about.com/library/weekly/aa011198.htm
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Public Seismic Network Mailing List (PSN-L)
Subject: Re: KINEMETRICS SEISMIC SENSOR
From: RADIOTEL@.......
Date: Sun, 4 Nov 2001 21:24:01 EST
TO: ALL LIST MEMBERS
There is a Kinemetrics TS-3 Seismic Sensor on Ebay #1657596668. Current bid
is $102.00. I have no idea whether it is a strong motion sensor, long period
sensor or broad band sensor.
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Subject: Re: KINEMETRICS SEISMIC SENSOR
From: Doug Crice dcrice@............
Date: Mon, 05 Nov 2001 07:01:01 -0800
I believe that this is a 3-component force balance accelerometer.
Kinemetrics made them from scratch in order to produce a
reasonably-priced product. It triggers on an earthquake and sends
analog data to a central recording system. It predates modern MEMS
accelerometers, will only detect strong local earthquakes, and should
only be purchased for a lot less than this vendor thinks it's worth. I'm
sure Larry's system will be better and reasonably priced.
RADIOTEL@....... wrote:
>
> TO: ALL LIST MEMBERS
> There is a Kinemetrics TS-3 Seismic Sensor on Ebay #1657596668. Current bid
> is $102.00. I have no idea whether it is a strong motion sensor, long period
> sensor or broad band sensor.
> __________________________________________________________
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Subject: laser seismograph
From: R&L Thompson rlthompson@.................
Date: Tue, 06 Nov 2001 15:34:05 -0330
I'd appreciate comments regarding this seismograph design using a laser.
http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm
I'm unqualified to say much about it, but I'm doubtful that it would be
very sensitive.
Ron (in Gander)
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Subject: Re: laser seismograph
From: "morris" morris@.......
Date: Tue, 6 Nov 2001 11:39:39 -0800
Let me know if you find any info on the laser seismo.
I have thought of using something like this.
Ron Suttora (Livermore)
morris@.......
----- Original Message -----
From: R&L Thompson <rlthompson@.................>
To: PSN List <PSN-L@..............>
Sent: Tuesday, November 06, 2001 11:04 AM
Subject: laser seismograph
> I'd appreciate comments regarding this seismograph design using a laser.
>
> http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm
>
> I'm unqualified to say much about it, but I'm doubtful that it would be
> very sensitive.
>
> Ron (in Gander)
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
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Subject: Re: laser seismograph
From: "ravakian" ravakian@............
Date: Tue, 6 Nov 2001 15:03:25 -0600
As shown I can't see how there would be any sensitivity at all, but
what about try stretching it out straight for a number of feet, say
at least 1/4 wavelength? Even then the big problem I see is the
non-directionality of the device. How do you tell horizontal from
vertical motion and either from a sag of the cable due to towards and
away motion?
Bob Avakian
Tulsa, OK
---- Original Message ----
From: morris@.......
To: psn-l@...............
Subject: Re: laser seismograph
Date: Tue, 6 Nov 2001 11:39:39 -0800
>Let me know if you find any info on the laser seismo.
>I have thought of using something like this.
>
>Ron Suttora (Livermore)
>morris@.......
>----- Original Message -----
>From: R&L Thompson <rlthompson@.................>
>To: PSN List <PSN-L@..............>
>Sent: Tuesday, November 06, 2001 11:04 AM
>Subject: laser seismograph
>
>
>> I'd appreciate comments regarding this seismograph design using a
>laser.
>>
>> http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm
>>
>> I'm unqualified to say much about it, but I'm doubtful that it
>would be
>> very sensitive.
>>
>> Ron (in Gander)
>>
>>
>> __________________________________________________________
>>
>> Public Seismic Network Mailing List (PSN-L)
>>
>> To leave this list email PSN-L-REQUEST@.............. with
>> the body of the message (first line only): unsubscribe
>> See http://www.seismicnet.com/maillist.html for more information.
>
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
>To leave this list email PSN-L-REQUEST@.............. with
>the body of the message (first line only): unsubscribe
>See http://www.seismicnet.com/maillist.html for more information.
>
>
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Subject: Re: laser seismograph
From: R&L Thompson rlthompson@.................
Date: Tue, 06 Nov 2001 17:47:37 -0330
Correct me if I'm wrong, but I think that 1/4 wavelength for an He laser
would be less than the diameter of the fiber, not much of a stretch.
Ron
ravakian wrote:
> As shown I can't see how there would be any sensitivity at all, but
> what about try stretching it out straight for a number of feet, say
> at least 1/4 wavelength? Even then the big problem I see is the
> non-directionality of the device. How do you tell horizontal from
> vertical motion and either from a sag of the cable due to towards and
> away motion?
>
> Bob Avakian
> Tulsa, OK
> ---- Original Message ----
> From: morris@.......
> To: psn-l@...............
> Subject: Re: laser seismograph
> Date: Tue, 6 Nov 2001 11:39:39 -0800
>
> >Let me know if you find any info on the laser seismo.
> >I have thought of using something like this.
> >
> >Ron Suttora (Livermore)
> >morris@.......
> >----- Original Message -----
> >From: R&L Thompson <rlthompson@.................>
> >To: PSN List <PSN-L@..............>
> >Sent: Tuesday, November 06, 2001 11:04 AM
> >Subject: laser seismograph
> >
> >
> >> I'd appreciate comments regarding this seismograph design using a
> >laser.
> >>
> >> http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm
> >>
> >> I'm unqualified to say much about it, but I'm doubtful that it
> >would be
> >> very sensitive.
> >>
> >> Ron (in Gander)
> >>
> >>
> >> __________________________________________________________
> >>
> >> Public Seismic Network Mailing List (PSN-L)
> >>
> >> To leave this list email PSN-L-REQUEST@.............. with
> >> the body of the message (first line only): unsubscribe
> >> See http://www.seismicnet.com/maillist.html for more information.
> >
> >__________________________________________________________
> >
> >Public Seismic Network Mailing List (PSN-L)
> >
> >To leave this list email PSN-L-REQUEST@.............. with
> >the body of the message (first line only): unsubscribe
> >See http://www.seismicnet.com/maillist.html for more information.
> >
> >
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
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Subject: Re: laser seismograph
From: ChrisAtUpw@.......
Date: Tue, 6 Nov 2001 19:42:06 EST
A LASER SEISMOGRAPH
EE488
Department of Electrical Engineering
University of Washington
Autumn Quarter, 1994 Proposal prepared by: Leslie Woitte and Richard Anderson
Hi All,
With the date 1994, there should be some record if this was ever tried
and what, if any, results were obtained. The article seems to lack any
logical relationship between a mechanical vibration and the 'noise' on the
output. The use of a lot of long words and a 741 amplifier does not
immediately inspire confidence in the scholarship of the proposal. Perhaps
someone who has a copy of the 'Laser Cookbook' would look it up the text
associated with Fig 16-9 and comment, please?
Regards,
Chris Chapman
<HTML><FONT FACE=arial,helvetica><P ALIGN=CENTER><FONT SIZE=2><B>A LASER SEISMOGRAPH
<BR><P ALIGN=LEFT></B>EE488
<BR>Department of Electrical Engineering
<BR>University of Washington
<BR>Autumn Quarter, 1994 Proposal prepared by: Leslie Woitte and Richard Anderson
<BR>
<BR>Hi All,
<BR> With the date 1994, there should be some record if this was ever tried and what, if an
y, results were obtained. The article seems to lack any logical relationship between a mechanical vibration and the 'noise' on
the output. The use of a lot of long words and a 741 amplifier does not immediately inspire confidence in the scholarship of th
e proposal. Perhaps someone who has a copy of the 'Laser Cookbook' would look it up the text associated with Fig 16-9 and comme
nt, please?
<BR> Regards,
<BR> Chris Chapman</P></P></FONT></HTML>
Subject: Re: laser seismograph
From: "Al Allworth" allworth@..............
Date: Tue, 6 Nov 2001 18:28:29 -0800
Hi,
This looks like it might be a poorly thought out attempt to build a =
device similar to
the laser ring detectors tried by those in New Zealand and elsewhere.
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<DIV><FONT size=3D2>Hi,</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>This looks like it might be a poorly thought out =
attempt to=20
build a device similar to</FONT></DIV>
<DIV><FONT size=3D2>the laser ring detectors tried by those in New =
Zealand=20
and elsewhere.</FONT></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"><FONT=20
size=3D2></FONT> </BLOCKQUOTE></BODY></HTML>
Subject: Re: laser seismograph
From: "Larry Cochrane" cochrane@..............
Date: Tue, 6 Nov 2001 18:40:43 -0800
I like the 741 op-amp circuit. It has three different ways of =
controlling the gain!
-Larry Cochrane
Redwood City, PSN
----- Original Message -----=20
From: Al Allworth=20
To: psn-l@.................
Sent: Tuesday, November 06, 2001 6:28 PM
Subject: Re: laser seismograph
Hi,
This looks like it might be a poorly thought out attempt to build a =
device similar to
the laser ring detectors tried by those in New Zealand and elsewhere.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; =
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<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>I like the 741 op-amp circuit. It has =
three=20
different ways of controlling the gain!</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>-Larry Cochrane</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Redwood City, PSN</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A title=3Dallworth@.............. =
href=3D"mailto:allworth@..............">Al=20
Allworth</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dpsn-l@.................
href=3D"mailto:psn-l@..............">psn-l@..............</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Tuesday, November 06, =
2001 6:28=20
PM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: laser =
seismograph</DIV>
<DIV><BR></DIV>
<DIV><FONT size=3D2>Hi,</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>This looks like it might be a poorly thought out =
attempt to=20
build a device similar to</FONT></DIV>
<DIV><FONT size=3D2>the laser ring detectors tried by those in =
New Zealand=20
and elsewhere.</FONT></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"><FONT=20
size=3D2></FONT> </BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>
Subject: Re: laser seismograph
From: John Hernlund hernlund@............
Date: Tue, 06 Nov 2001 18:48:47 -0800
A friend of mine has co-developed a laser seismograph. Really, it is a
strain meter. The way it works is to lay out a long line of fiber optic
cable and bounce light signals. One end is reflecting, while the other
end has a transmitter/receiver. The "time of flight" variations give
you the change in length. Dividing the change in length by the over all
length gives the strain as a function of time. His large prototype is
buried in his back yard in Kansas...
He caught on to this while gabbing with an engineer who uses this same
technique to measure strain in structures (eg. bridges) and apparently
it works quite well. They are working on a proposal to rent fiber
optics communications lines and hook this stuff up...it could be a lot
of fun. The longer term arm-waving goal is to eventually measure
precursory strain transients near an active fault (eg. San Andreas).
They could also work on other fun problems with sufficient sensitivity,
such as the Chandler wobble...
Most people I have known prefer an interferometric method to time of
flight methods, but I am not sure how each technique stacks up against
the other with the current technology. The interferometric method uses
a steady transmitted signal and measures the relative interference of
the waves to back out the changes in length. For a laser with a
wavelength around 500 nm, the resolution is a small fraction of this.
Averaged out over a very long cable, this would allow very small strains
to be measured. The nice thing about these types of instruments is that
they are truly broadband...limited only by the number and frequency of
measurements.
The astronomers working on binocularizing the Keck scope have run into
difficulties in connecting the two sources via an underground
tunnel...this also uses interferometric methods. I wonder how they are
doing now; whether they have fixed this problem or not. It may be
interesting to find out how they fix it all, since the Keck could easily
become a strain meter as well as a bad ass telescope when they do figure
it out.
Cheers!
John Hernlund
Department of Earth and Space Sciences
University of California, Los Angeles
http://geodyn.ess.ucla.edu/~hernlund/
hernlund@............
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: laser seismograph
From: "ed thelen" ethelen@........
Date: Tue, 6 Nov 2001 20:52:33 -0800
You have me curious -
How is the 747 different from any other noisy, drifty, hi-input current,
op-amp from the early 1970's ??
Feedback is feedback isn't it?
The modern op-amp designs seem so much better.
"I'd walk a mile for a camel - no no that should be chopper stabilization."
(And I have used my share of 747's when they were about
the only game in town "for the rest of us".)
Cheers
Ed Thelen
----- Original Message -----
> From: "Larry Cochrane" <cochrane@..............>
>
> I like the 741 op-amp circuit. It has three different ways of controlling
the gain!
>
> -Larry Cochrane
> Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: laser seismograph
From: "Larry Cochrane" cochrane@..............
Date: Tue, 6 Nov 2001 22:32:45 -0800
Ed, I wasn't commenting on the type of op-amp. Obviously there are a lot
better op-amps then the 741. What I was commenting on was the three gain
control pots.
-Larry
----- Original Message -----
From: "ed thelen" <ethelen@........>
To: <psn-l@..............>
Sent: Tuesday, November 06, 2001 8:52 PM
Subject: Re: laser seismograph
> You have me curious -
> How is the 747 different from any other noisy, drifty, hi-input current,
> op-amp from the early 1970's ??
>
> Feedback is feedback isn't it?
>
> The modern op-amp designs seem so much better.
> "I'd walk a mile for a camel - no no that should be chopper
stabilization."
>
> (And I have used my share of 747's when they were about
> the only game in town "for the rest of us".)
>
> Cheers
> Ed Thelen
>
> ----- Original Message -----
> > From: "Larry Cochrane" <cochrane@..............>
> >
> > I like the 741 op-amp circuit. It has three different ways of
controlling
> the gain!
> >
> > -Larry Cochrane
> > Redwood City, PSN
>
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: RE: laser seismograph
From: "Ron Westfall" westfall@........
Date: Tue, 6 Nov 2001 23:12:35 -0800
Hi
I have a copy of the Laser Cookbook. I got it because I was intrigued by
the idea of a laser-based
seismograph.
The web page that Ron Thompson referred us to was for a class project
(presumably for a class
that dealt with lasers). Some of the other projects look interesting by the
way. It looks like the two
students who wrote the web page pretty much borrowed the design directly
from the Laser
Cookbook.
Apparently, in a stepped-index fiber, laser light travels through the fiber
in several groups of light
beams. At the transmitting laser, all the light beams have exactly the same
phase (a basic property
of laser light known as coherency). As the light beams travel along the
stepped-index fiber, the
phase of each group of light beams changes relative to the other groups.
Apparently, if the fiber
is long enough, the light coming out the far end is completely incoherent
(i.e. the optical equivalent
of mush, or ordinary light).
By using only 10 - 20 feet of fiber in the seismograph, coherency is only
partly degraded. When
the laser light is detected by a phototransistor and the resulting
electrical signal is amplified, the
slight differences in phase relationship between the groups of light beams
creates low frequency
audio noise. Based on the description given in the Laser Cookbook, I am
guessing that the audio
noise is fairly constant in the absence of changes in geometry of the fiber.
The changes in phase relationship are sensitive to length of the fiber as
mentioned and curvature.
I wouldn't be surprised if temperature causes changes as well. Vibration
dynamically changes
the curvature of the fiber causing dynamic changes in phase relationship.
The audio noise
generated by the phototransistor changes. The Laser Cookbook mentions that
the noise "changes
pitch and makes odd thuds, pings, and thrums". The Cookbook does not
provide a precise
analysis of the changes in phase relationship, so the mathematical
relationship between the
changing noise and the original vibration is unclear.
Figure 4 (16-3 in the Cookbook) gives the mechanical structure of the
seismograph. As Bob
Avakian has pointed out, the device is non-directional because the fiber is
wound around
four bolts in a rectangle, so the fiber will have both N-S and E-W
components of motion. Because
the fiber can move in a vertical direction, there will also be a vertical
component.
Some degree of directionality could be achieved by using only two bolts
oriented in a N-S or E-W
direction. You would unfortunately still have a vertical component mixed
in. The other problem I
can see is that the fiber motion is not damped.
Figure 5 (15-9 in the Cookbook) provides the schematic for the
phototransistor and amplifier. In
Figure 15-9 in the Cookbook there is an LM386 audio amplifier chip that is
fed by the output of
the LM741. In Figure 5 from the web page, the potentiometer wiper output
lead is connected to the
positive input of the 386 and the negative input of the 386 is grounded as
indicated by the other
output lead in Figure 5. The output of the 386 is capactively coupled (220
uF) to a headphone
jack.
The author of the cookbook built the seismograph and detected a quake in the
Los Angeles area
on October 1, 1987. The M6.1 quake was 50 miles away from the seismograph.
Hopefully that was interesting. If you have any other questions that I can
answer by digging
through the Cookbook, let me know.
Ron Westfall
-----Original Message-----
From: psn-l-request@.............. [mailto:psn-l-request@.................
Behalf Of ChrisAtUpw@.......
Sent: Tuesday, November 06, 2001 4:42 PM
To: psn-l@..............
Subject: Re: laser seismograph
A LASER SEISMOGRAPH
EE488
Department of Electrical Engineering
University of Washington
Autumn Quarter, 1994 Proposal prepared by: Leslie Woitte and Richard
Anderson
Hi All,
With the date 1994, there should be some record if this was ever
tried and what, if any, results were obtained. The article seems to lack any
logical relationship between a mechanical vibration and the 'noise' on the
output. The use of a lot of long words and a 741 amplifier does not
immediately inspire confidence in the scholarship of the proposal. Perhaps
someone who has a copy of the 'Laser Cookbook' would look it up the text
associated with Fig 16-9 and comment, please?
Regards,
Chris Chapman
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 5.50.4522.1800" name=3DGENERATOR></HEAD>
<BODY>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>Hi</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>I have=20
a copy of the Laser Cookbook. I got it because I was intrigued by =
the idea=20
of a laser-based</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>seismograph.</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>The=20
web page that Ron Thompson referred us to was for a class project =
(presumably=20
for a class</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>that=20
dealt with lasers). Some of the other projects look interesting by =
the=20
way. It looks like the two</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>students who wrote the web page pretty much borrowed the design =
directly=20
from the Laser</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>Cookbook.</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>Apparently, in a stepped-index fiber, laser light travels =
through the=20
fiber in several groups of light</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>beams. At the transmitting laser, all the light beams =
have exactly=20
the same phase (a basic property</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>of=20
laser light known as coherency). </FONT></SPAN><SPAN=20
class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>As the=20
</FONT></SPAN><SPAN class=3D470223206-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2>light beams travel along the stepped-index fiber, =
the</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>phase=20
of each group of light beams changes relative to the other groups. =
Apparently, if the fiber</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>is=20
long enough, the light coming out the far end is completely incoherent =
(i.e. the=20
optical equivalent</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>of=20
mush, or ordinary light).</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>By=20
using only 10 - 20 feet </FONT></SPAN><SPAN =
class=3D470223206-07112001><FONT=20
face=3DArial color=3D#0000ff size=3D2>of fiber in the seismograph, =
coherency is only=20
</FONT></SPAN><SPAN class=3D470223206-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2>partly degraded. When</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>the=20
laser light is detected by a phototransistor and the resulting =
electrical=20
</FONT></SPAN><SPAN class=3D470223206-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2>signal is amplified, the</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>slight=20
differences in phase relationship between the groups of light beams=20
</FONT></SPAN><SPAN class=3D470223206-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2>creates low frequency</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>audio=20
noise. Based on the description given in the Laser Cookbook, I am =
guessing=20
that the audio</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>noise=20
is fairly constant in </FONT></SPAN><SPAN =
class=3D470223206-07112001><FONT=20
face=3DArial color=3D#0000ff size=3D2>the absence of changes in geometry =
of the=20
fiber.</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>The=20
changes in phase relationship are sensitive to length of the fiber as =
mentioned=20
</FONT></SPAN><SPAN class=3D470223206-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2>and curvature.</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>I=20
wouldn't be surprised if temperature causes changes as well. =20
</FONT></SPAN><SPAN class=3D470223206-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2>Vibration dynamically changes</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>the=20
curvature of the fiber causing dynamic changes in phase =
</FONT></SPAN><SPAN=20
class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff=20
size=3D2>relationship. The audio noise</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>generated by the phototransistor changes. The Laser =
Cookbook=20
</FONT></SPAN><SPAN class=3D470223206-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2>mentions that the noise "changes</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>pitch=20
and makes odd thuds, pings, and thrums". The Cookbook does not =
provide a=20
precise</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>analysis of the changes in phase relationship, so the =
mathematical=20
relationship between the</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>changing noise and the original vibration is =
unclear.</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>Figure=20
4 (16-3 in the Cookbook) gives the mechanical structure of the=20
seismograph. As Bob</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>Avakian has pointed out, the device is non-directional because =
the fiber=20
is wound around</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>four=20
bolts in a rectangle, so the fiber will have both N-S and E-W components =
of=20
motion. Because</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>the=20
fiber can move in a vertical direction, there will also be a vertical=20
component.</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>Some=20
degree of directionality could be achieved by using only two=20
bolts </FONT></SPAN><SPAN class=3D470223206-07112001><FONT =
face=3DArial=20
color=3D#0000ff size=3D2>oriented in a N-S or E-W</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>direction. You would unfortunately still have a vertical =
component=20
mixed in. The other problem I</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>can=20
see is that the fiber motion is not damped.</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>Figure=20
5 (15-9 in the Cookbook) provides the schematic for the phototransistor =
and=20
amplifier. In</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>Figure=20
15-9 in the Cookbook there is an LM386 audio amplifier chip that is fed =
by the=20
output of</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>the=20
LM741. In Figure 5 from the web page, the potentiometer wiper =
output lead=20
is connected to the</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>positive input of the 386 and the negative input of the 386 is =
grounded=20
as indicated by the other</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>output=20
lead in Figure 5. The output of the 386 is capactively coupled =
(220 uF) to=20
a headphone</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>jack.</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>The=20
author of the cookbook built the seismograph and detected a quake in the =
Los=20
Angeles area</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>on=20
October 1, 1987. The M6.1 quake was 50 miles away from the=20
seismograph.</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>Hopefully that was interesting. If you have any other =
questions=20
that I can answer by digging</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>through the Cookbook, let me know.</FONT></SPAN></DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D470223206-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>Ron=20
Westfall</FONT></SPAN></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px =
solid; MARGIN-RIGHT: 0px">
<DIV class=3DOutlookMessageHeader dir=3Dltr align=3Dleft><FONT =
face=3DTahoma=20
size=3D2>-----Original Message-----<BR><B>From:</B> =
psn-l-request@.................
[mailto:psn-l-request@...............<B>On Behalf Of=20
</B>ChrisAtUpw@.......<BR><B>Sent:</B> Tuesday, November 06, 2001 4:42 =
PM<BR><B>To:</B> psn-l@..............<BR><B>Subject:</B> Re: laser=20
seismograph<BR><BR></FONT></DIV><FONT face=3Darial,helvetica>
<P align=3Dcenter><FONT size=3D2><B>A LASER SEISMOGRAPH <BR>
<P align=3Dleft></B>EE488 <BR>Department of Electrical Engineering=20
<BR>University of Washington <BR>Autumn Quarter, 1994 Proposal =
prepared by:=20
Leslie Woitte and Richard Anderson <BR><BR>Hi All,=20
<BR> With the date 1994, there =
should be=20
some record if this was ever tried and what, if any, results were =
obtained.=20
The article seems to lack any logical relationship between a =
mechanical=20
vibration and the 'noise' on the output. The use of a lot of long =
words and a=20
741 amplifier does not immediately inspire confidence in the =
scholarship of=20
the proposal. Perhaps someone who has a copy of the 'Laser Cookbook' =
would=20
look it up the text associated with Fig 16-9 and comment, please?=20
<BR> Regards,=20
<BR> Chris Chapman</P>
<P></P></BLOCKQUOTE></FONT></FONT></BODY></HTML>
Subject: Re: laser seismograph
From: CapAAVSO@.......
Date: Wed, 7 Nov 2001 07:43:48 EST
In a message dated 11/7/01 8:13:18 AM GMT Standard Time, westfall@........
writes:
> I have a copy of the Laser Cookbook. I got it because I was intrigued by
> the idea of a laser-based seismograph.
Hi Ron,
Is the laser cookbook still available? If so, where can I buy a copy?
Thanks,
Cap
<FONT SIZE=2>In a message dated 11/7/01 8:13:18 AM GMT Standard Time, westfall@........ writes:<BR>
<BR>
<BR>
</FONT><FONT COLOR="#0000ff" style="BACKGROUND-COLOR: #ffffff" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0"><BLOCKQUOTE TYP
E=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">I have a copy of the Lase
r Cookbook. I got it because I was intrigued by the idea of a laser-based</FONT><FONT COLOR="#000000" style="BACKGROUND-
COLOR: #ffffff" SIZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG="0"> </FONT><FONT COLOR="#0000ff" style="BACKGROUND-COLOR: #ffffff
" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">seismograph.</FONT><FONT COLOR="#000000" style="BACKGROUND-COLOR: #ffffff" S
IZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG="0"></BLOCKQUOTE><BR>
</FONT><FONT COLOR="#000000" style="BACKGROUND-COLOR: #ffffff" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0"><BR>
Hi Ron,<BR>
<BR>
Is the laser cookbook still available? If so, where can I buy a copy?<BR>
<BR>
Thanks,<BR>
Cap<BR>
</FONT></HTML>
Subject: AW: laser seismograph
From: "Fund, Norbert" Norbert.Fund@..............
Date: Wed, 7 Nov 2001 13:57:56 +0100
Hi All,
=20
I found this interesting article by Leslie Woitte and Richard Anderson =
due a
Google search:
=20
http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm
<http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm>=20
=20
Norbert Fund =20
-----Urspr=FCngliche Nachricht-----
Von: CapAAVSO@....... [mailto:CapAAVSO@........
Gesendet: Mittwoch, 7. November 2001 13:44
An: psn-l@..............
Betreff: Re: laser seismograph
In a message dated 11/7/01 8:13:18 AM GMT Standard Time, =
westfall@........
writes:
I have a copy of the Laser Cookbook. I got it because I was intrigued =
by
the idea of a laser-based seismograph.
Hi Ron,
Is the laser cookbook still available? If so, where can I buy a copy?
Thanks,
Cap
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META HTTP-EQUIV=3D"Content-Type" CONTENT=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 6.00.2600.0" name=3DGENERATOR></HEAD>
<BODY>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff size=3D2>Hi=20
All,</FONT></SPAN></DIV>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff size=3D2>I=20
found this interesting article by <FONT face=3D"Times New Roman"=20
color=3D#000000 size=3D3>Leslie Woitte and Richard Anderson </FONT>due =
a Google=20
search:</FONT></SPAN></DIV>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff size=3D2><A=20
href=3D"http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.ht=
m">http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm</A>=
</FONT></SPAN></DIV>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2>Norbert Fund </FONT></SPAN></DIV>
<BLOCKQUOTE>
<DIV class=3DOutlookMessageHeader dir=3Dltr align=3Dleft><FONT =
face=3DTahoma=20
size=3D2>-----Urspr=FCngliche Nachricht-----<BR><B>Von:</B> =
CapAAVSO@..........
[mailto:CapAAVSO@........<BR><B>Gesendet:</B> Mittwoch, 7. November =
2001=20
13:44<BR><B>An:</B> psn-l@..............<BR><B>Betreff:</B> Re: laser =
seismograph<BR><BR></FONT></DIV><FONT size=3D2>In a message dated =
11/7/01=20
8:13:18 AM GMT Standard Time, westfall@...........
writes:<BR><BR><BR></FONT><FONT lang=3D0 style=3D"BACKGROUND-COLOR: =
#ffffff"=20
face=3DArial color=3D#0000ff size=3D2 FAMILY=3D"SANSSERIF">
<BLOCKQUOTE=20
style=3D"PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff =
2px solid; MARGIN-RIGHT: 0px"=20
TYPE=3D"CITE">I have a copy of the Laser Cookbook. I got it =
because I=20
was intrigued by the idea of a laser-based</FONT><FONT lang=3D0=20
style=3D"BACKGROUND-COLOR: #ffffff" face=3DArial color=3D#000000 =
size=3D3=20
FAMILY=3D"SANSSERIF"> </FONT><FONT lang=3D0 =
style=3D"BACKGROUND-COLOR: #ffffff"=20
face=3DArial color=3D#0000ff size=3D2 =
FAMILY=3D"SANSSERIF">seismograph.</FONT><FONT=20
lang=3D0 style=3D"BACKGROUND-COLOR: #ffffff" face=3DArial =
color=3D#000000 size=3D3=20
FAMILY=3D"SANSSERIF"></BLOCKQUOTE><BR></FONT><FONT lang=3D0=20
style=3D"BACKGROUND-COLOR: #ffffff" face=3DArial color=3D#000000 =
size=3D2=20
FAMILY=3D"SANSSERIF"><BR>Hi Ron,<BR><BR>Is the laser cookbook still =
available?=20
If so, where can I buy a=20
copy?<BR><BR>Thanks,<BR>Cap<BR></BLOCKQUOTE></FONT></BODY></HTML>
Subject: AW: laser seismograph
From: "Fund, Norbert" Norbert.Fund@..............
Date: Wed, 7 Nov 2001 14:27:58 +0100
Ahhh! Please delete! Stupid, I got this message BEFORE the forgoing =
ones.
Sorry!!
-----Urspr=FCngliche Nachricht-----
Von: Fund, Norbert=20
Gesendet: Mittwoch, 7. November 2001 13:59
An: 'psn-l@...............
Betreff: AW: laser seismograph
Hi All,
=20
I found this interesting article by Leslie Woitte and Richard Anderson =
due a
Google search:
=20
http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm
<http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm>=20
=20
Norbert Fund =20
=20
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META HTTP-EQUIV=3D"Content-Type" CONTENT=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 6.00.2600.0" name=3DGENERATOR></HEAD>
<BODY>
<DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN =
class=3D611322013-07112001>Ahhh!=20
Please delete! Stupid, I got this message BEFORE the forgoing ones.=20
Sorry!!</SPAN></FONT></DIV>
<BLOCKQUOTE dir=3Dltr style=3D"MARGIN-RIGHT: 0px">
<DIV class=3DOutlookMessageHeader dir=3Dltr align=3Dleft><FONT =
face=3DTahoma=20
size=3D2>-----Urspr=FCngliche Nachricht-----<BR><B>Von:</B> Fund, =
Norbert=20
<BR><B>Gesendet:</B> Mittwoch, 7. November 2001 13:59<BR><B>An:</B>=20
'psn-l@...............<BR><B>Betreff:</B> AW: laser=20
seismograph<BR><BR></FONT></DIV>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff size=3D2>Hi=20
All,</FONT></SPAN></DIV>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff size=3D2>I=20
found this interesting article by <FONT face=3D"Times New Roman" =
color=3D#000000 size=3D3>Leslie Woitte and Richard Anderson =
</FONT>due=20
a Google search:</FONT></SPAN></DIV>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff size=3D2><A=20
=
href=3D"http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.ht=
m">http://www.ece.orst.edu/~ece482/lasers/ee48894/leslie/lesprop.htm</A>=
</FONT></SPAN></DIV>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D469454812-07112001><FONT face=3DArial =
color=3D#0000ff=20
size=3D2>Norbert Fund </FONT></SPAN></DIV>
<BLOCKQUOTE> </BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>
Subject: Re: laser seismograph
From: ChrisAtUpw@.......
Date: Wed, 7 Nov 2001 08:51:47 EST
In a message dated 07/11/2001, CapAAVSO@....... writes:
> Is the laser cookbook still available? If so, where can I buy a copy?
>
Hi Cap,
'The Laser Cookbook' by Gordon McComb 1988 ISBN 0830693904 is listed
by Amazon.com @ $20.96 new & $15.99 used.
Regards,
Chris Chapman
<HTML><FONT FACE=arial,helvetica><FONT SIZE=2>In a message dated 07/11/2001, CapAAVSO@....... writes:
<BR>
<BR><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Is the
laser cookbook still available? If so, where can I buy a copy?
<BR></FONT><FONT COLOR="#000000" SIZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG="0"></BLOCKQUOTE>
<BR></FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">Hi Cap,
<BR> 'The Laser Cookbook' by Gordon McComb 1988 ISBN 0830693904 is listed by Amazon.com @ $
20.96 new & $15.99 used.
<BR> Regards,
<BR> Chris Chapman</FONT></HTML>
Subject: Re: laser seismograph
From: "Ron Westfall" westfall@........
Date: Wed, 7 Nov 2001 10:03:13 -0800
Cap
As Chris mentioned, it is available at Amazon. Here is the URL:
http://www.amazon.com/exec/obidos/ASIN/0830693904/qid=1005158189/sr=1-2/ref=
sr_1_6_2/102-9033424-7078543
When I searched Amazon, I also came across the book Optoelectronics, Fiber
Optics, and Laser Cookbook by
Thomas Petruzzellis. I noticed with interest that it also has about 7 pages
dedicated to laser seismometers. Here
is the URL for that one as well:
http://www.amazon.com/exec/obidos/ASIN/0070498407/ref=pd_sim_books/102-90334
24-7078543
Ron
-----Original Message-----
From: psn-l-request@.............. [mailto:psn-l-request@.................
Behalf Of CapAAVSO@.......
Sent: Wednesday, November 07, 2001 4:44 AM
To: psn-l@..............
Subject: Re: laser seismograph
In a message dated 11/7/01 8:13:18 AM GMT Standard Time, westfall@........
writes:
I have a copy of the Laser Cookbook. I got it because I was intrigued
by the idea of a laser-based seismograph.
Hi Ron,
Is the laser cookbook still available? If so, where can I buy a copy?
Thanks,
Cap
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE></TITLE>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 5.50.4522.1800" name=3DGENERATOR></HEAD>
<BODY><FONT face=3DArial size=3D2>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>Cap</FONT></SPAN></DIV>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>As=20
Chris mentioned, it is available at Amazon. Here is the=20
URL:</FONT></SPAN></DIV>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial size=3D2><A=20
href=3D"http://www.amazon.com/exec/obidos/ASIN/0830693904/qid=3D100515818=
9/sr=3D1-2/ref=3Dsr_1_6_2/102-9033424-7078543">http://www.amazon.com/exec=
/obidos/ASIN/0830693904/qid=3D1005158189/sr=3D1-2/ref=3Dsr_1_6_2/102-9033=
424-7078543</A></FONT></SPAN></DIV>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>When I=20
searched Amazon, I also came across the book Optoelectronics, Fiber =
Optics, and=20
Laser Cookbook by</FONT></SPAN></DIV>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>Thomas=20
Petruzzellis. I noticed with interest that it also has =
about <SPAN=20
class=3D920415317-07112001>7</SPAN> pages dedicated to laser =
seismometers. =20
Here</FONT></SPAN></DIV>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>is the=20
URL for that one as well:</FONT></SPAN></DIV>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2><A=20
href=3D"http://www.amazon.com/exec/obidos/ASIN/0070498407/ref=3Dpd_sim_bo=
oks/102-9033424-7078543">http://www.amazon.com/exec/obidos/ASIN/007049840=
7/ref=3Dpd_sim_books/102-9033424-7078543</A></FONT></SPAN></DIV>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2>Ron</FONT></SPAN></DIV>
<DIV><SPAN class=3D090224817-07112001><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<BLOCKQUOTE=20
style=3D"PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px =
solid">
<DIV class=3DOutlookMessageHeader dir=3Dltr align=3Dleft><FONT =
face=3DTahoma=20
size=3D2>-----Original Message-----<BR><B>From:</B> =
psn-l-request@.................
[mailto:psn-l-request@...............<B>On Behalf Of=20
</B>CapAAVSO@.......<BR><B>Sent:</B> Wednesday, November 07, 2001 4:44 =
AM<BR><B>To:</B> psn-l@..............<BR><B>Subject:</B> Re: laser=20
seismograph<BR><BR></FONT></DIV><FONT size=3D2>In a message dated =
11/7/01=20
8:13:18 AM GMT Standard Time, westfall@...........
writes:<BR><BR><BR></FONT><FONT lang=3D0 style=3D"BACKGROUND-COLOR: =
#ffffff"=20
face=3DArial color=3D#0000ff size=3D2 FAMILY=3D"SANSSERIF">
<BLOCKQUOTE=20
style=3D"PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px =
solid; MARGIN-RIGHT: 0px"=20
TYPE=3D"CITE">I have a copy of the Laser Cookbook. I got it =
because I=20
was intrigued by the idea of a laser-based</FONT><FONT lang=3D0=20
style=3D"BACKGROUND-COLOR: #ffffff" face=3DArial color=3D#000000 =
size=3D3=20
FAMILY=3D"SANSSERIF"> </FONT><FONT lang=3D0 =
style=3D"BACKGROUND-COLOR: #ffffff"=20
face=3DArial color=3D#0000ff size=3D2 =
FAMILY=3D"SANSSERIF">seismograph.</FONT><FONT=20
lang=3D0 style=3D"BACKGROUND-COLOR: #ffffff" face=3DArial =
color=3D#000000 size=3D3=20
FAMILY=3D"SANSSERIF"></BLOCKQUOTE><BR></FONT><FONT lang=3D0=20
style=3D"BACKGROUND-COLOR: #ffffff" face=3DArial color=3D#000000 =
size=3D2=20
FAMILY=3D"SANSSERIF"><BR>Hi Ron,<BR><BR>Is the laser cookbook still =
available?=20
If so, where can I buy a=20
copy?<BR><BR>Thanks,<BR>Cap<BR></BLOCKQUOTE></FONT></FONT></BODY></HTML>
Subject: New sensor on line and available for sale
From: "Larry Cochrane" cochrane@..............
Date: Wed, 7 Nov 2001 16:01:39 -0800
All,
I now have one of my new accelerometer sensor boards online. The event files
will be *.lcanh.psn (N-S), *.lcaeh.psn (E-W) and *.lcazh.psn (vertical). A
picture of the board as well as more information about the sensor board can
be found here: http://www.seismicnet.com/psnaccel/
I currently have 10 blank PC boards and 11 ICS3052-002 sensors chips
in-stock. Each sensor chip is one axis so I'm limited on the number of
channels I can send out immediately. I contacted the manufacture yesterday
to fined out the statues of the part. They do not have any in-stock and the
part has a 6 week lead time. The sales person said there was a backlog on
the part so they should be making more soon.
So what I have to do is figure out how may sensors chips to order. In single
quantities the part costs $199.00 through Digi-Key. The price drops to
$134.00 for 10, $114.00 for 25 and $102.00 for 100. The prices on my web
page are based on the parts costing around $134.00. I would like to by the
sensors in quantities of 100 so I could drop the price a little but I don't
want to put out $10K unless I can sell them in a few months.
If you would like to order one or more of the sensor boards please email me.
Note that this type of sensor, like a geophone, will only record local and
large regional events. It will not pickup distant or teleseismic events.
Regards,
Larry Cochrane
Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: laser seismograph
From: CapAAVSO@.......
Date: Wed, 7 Nov 2001 21:43:43 EST
In a message dated 11/7/01 7:04:00 PM GMT Standard Time, westfall@........
writes:
> When I searched Amazon, I also came across the book Optoelectronics, Fiber
> Optics, and Laser Cookbook by
> Thomas Petruzzellis. I noticed with interest that it also has about 7
> pages dedicated to laser seismometers. Here
> is the URL for that one as well:
>
Thanks Ron and Chris,
I decided the above book would be more useful than the "Laser Cookbook" so
bought a used copy through Amazon for $15.50.
Thanks again,
Cap
<FONT SIZE=2>In a message dated 11/7/01 7:04:00 PM GMT Standard Time, westfall@........ writes:<BR>
<BR>
<BR>
<BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">When I sea
rched Amazon, I also came across the book Optoelectronics, Fiber Optics, and Laser Cookbook by<BR>
</FONT><FONT COLOR="#0000ff" style="BACKGROUND-COLOR: #ffffff" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">Thomas Petruzze
llis. I noticed with interest that it also has about 7 pages dedicated to laser seismometers. Here</FONT><FONT COL
OR="#000000" style="BACKGROUND-COLOR: #ffffff" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0"><BR>
</FONT><FONT COLOR="#0000ff" style="BACKGROUND-COLOR: #ffffff" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">is the URL for
that one as well:</FONT><FONT COLOR="#000000" style="BACKGROUND-COLOR: #ffffff" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0
"><BR>
</BLOCKQUOTE><BR>
<BR>
Thanks Ron and Chris,<BR>
<BR>
I decided the above book would be more useful than the "Laser Cookbook" so bought a used copy through Amazon for $15.50.<BR>
<BR>
Thanks again,<BR>
Cap</FONT></HTML>
Subject: Re: accelerometer chip recording of China quake?
From: "Larry Cochrane" cochrane@..............
Date: Wed, 14 Nov 2001 17:58:23 -0800
Bob,
No it didn't, nor would I expect it too. This type of sensor will only
record local events. The FBA-23 accelerometer sensor also did not record it
and it's 6 to 7 times more sensitive then the new sensor.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: <Bob_Hammond@..........>
To: <cochrane@..............>
Sent: Wednesday, November 14, 2001 3:04 PM
Subject: accelerometer chip recording of China quake?
> Larry, I'm curious as to what the waveforms look like for the China quake
> from your piezoresistive accelerometers.
>
> regards,
>
> Bob Hammond
> APSN
> Fairbanks
>
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Publication on the Web
From: ACole65464@.......
Date: Sat, 17 Nov 2001 11:09:55 EST
Hello everyone,
While doing a Web search I came across a paper containing information that
may be of interest to some of you, titled "Instrumentation in Earthquake
Seismology", written by Jens Havskov and Gerardo Alguacil. Its a large 3.6
meg PDF file, 264 pages in length, which will take some time to download, but
worth it if you save it to your hard disk. It expands on the papers by Prof.
Erhard Wielandt (titled "Seismometry" and "Seismic Sensors and Their
Calibration"). The new document pulls together material from several
resources, including Wielandt's papers. The paper is a preliminary release,
you will find some typing and grammar errors. Go to:
http://www.ifjf.uib.no/seismo/SOFTWARE/OTHER/instrument.pdf
It may be worthy enough to have a link to it on Larry's Web site. Any
comments?
Regards,
Allan Coleman
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Publication on the Web
From: "jimesler" jimesler@..........
Date: Sat, 17 Nov 2001 16:39:45 -0600
Is there some trick to being able to save this off to a hard disk - mine
will not allow me to....
Does anyone have any experiences in building an inferometer for measuring
displacement in seismographs?
Jim Esler
----- Original Message -----
From: <ACole65464@.......>
To: <psn-l@..............>
Sent: Saturday, November 17, 2001 10:09 AM
Subject: Publication on the Web
> Hello everyone,
>
> While doing a Web search I came across a paper containing information that
> may be of interest to some of you, titled "Instrumentation in Earthquake
> Seismology", written by Jens Havskov and Gerardo Alguacil. Its a large 3.6
> meg PDF file, 264 pages in length, which will take some time to download,
but
> worth it if you save it to your hard disk. It expands on the papers by
Prof.
> Erhard Wielandt (titled "Seismometry" and "Seismic Sensors and Their
> Calibration"). The new document pulls together material from several
> resources, including Wielandt's papers. The paper is a preliminary
release,
> you will find some typing and grammar errors. Go to:
>
> http://www.ifjf.uib.no/seismo/SOFTWARE/OTHER/instrument.pdf
>
> It may be worthy enough to have a link to it on Larry's Web site. Any
> comments?
>
> Regards,
>
> Allan Coleman
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Publication on the Web
From: Terence Dowling dowling@.........
Date: Sat, 17 Nov 2001 13:16:48 -1000
It worked fine for me using the "Save As" option.
If others have trouble with this I'd be happy to e-mail the
document.
Terry
jimesler wrote:
>
> Is there some trick to being able to save this off to a hard disk - mine
> will not allow me to....
>
> Does anyone have any experiences in building an inferometer for measuring
> displacement in seismographs?
>
> Jim Esler
>
> ----- Original Message -----
> From: <ACole65464@.......>
> To: <psn-l@..............>
> Sent: Saturday, November 17, 2001 10:09 AM
> Subject: Publication on the Web
>
> > Hello everyone,
> >
> > While doing a Web search I came across a paper containing information that
> > may be of interest to some of you, titled "Instrumentation in Earthquake
> > Seismology", written by Jens Havskov and Gerardo Alguacil. Its a large 3.6
> > meg PDF file, 264 pages in length, which will take some time to download,
> but
> > worth it if you save it to your hard disk. It expands on the papers by
> Prof.
> > Erhard Wielandt (titled "Seismometry" and "Seismic Sensors and Their
> > Calibration"). The new document pulls together material from several
> > resources, including Wielandt's papers. The paper is a preliminary
> release,
> > you will find some typing and grammar errors. Go to:
> >
> > http://www.ifjf.uib.no/seismo/SOFTWARE/OTHER/instrument.pdf
> >
> > It may be worthy enough to have a link to it on Larry's Web site. Any
> > comments?
> >
> > Regards,
> >
> > Allan Coleman
> >
> > __________________________________________________________
> >
> > Public Seismic Network Mailing List (PSN-L)
> >
> > To leave this list email PSN-L-REQUEST@.............. with
> > the body of the message (first line only): unsubscribe
> > See http://www.seismicnet.com/maillist.html for more information.
> >
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
--
Terence Dowling (808) 884-5175 (GMT -10)
Adobe Systems Inc. dowling@.........
Nominal Work Day (7:00 AM HST - 9:00 AM PST) to
(4:00 PM HST - 6:00 PM PST)
Please don't call before (7:00 AM HST - 9:00 AM PST)
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Publication on the Web
From: Karl Cunningham karlc@..........
Date: Sat, 17 Nov 2001 15:41:31 -0800
I had the same problem. Try this: instead of going to the location in
Allan's email, go to the parent directory:
http://www.ifjf.uib.no/seismo/SOFTWARE/OTHER
Then right click on the instrument.pdf link and select download.
Karl Cunningham
--On Saturday, November 17, 2001 16:39 -0600 jimesler <jimesler@..........>
wrote:
> Is there some trick to being able to save this off to a hard disk - mine
> will not allow me to....
>
> Does anyone have any experiences in building an inferometer for measuring
> displacement in seismographs?
>
> Jim Esler
>
>
> ----- Original Message -----
> From: <ACole65464@.......>
> To: <psn-l@..............>
> Sent: Saturday, November 17, 2001 10:09 AM
> Subject: Publication on the Web
>
>
>> Hello everyone,
>>
>> While doing a Web search I came across a paper containing information
>> that may be of interest to some of you, titled "Instrumentation in
>> Earthquake Seismology", written by Jens Havskov and Gerardo Alguacil.
>> Its a large 3.6 meg PDF file, 264 pages in length, which will take some
>> time to download,
> but
>> worth it if you save it to your hard disk. It expands on the papers by
> Prof.
>> Erhard Wielandt (titled "Seismometry" and "Seismic Sensors and Their
>> Calibration"). The new document pulls together material from several
>> resources, including Wielandt's papers. The paper is a preliminary
> release,
>> you will find some typing and grammar errors. Go to:
>>
>> http://www.ifjf.uib.no/seismo/SOFTWARE/OTHER/instrument.pdf
>>
>> It may be worthy enough to have a link to it on Larry's Web site. Any
>> comments?
>>
>> Regards,
>>
>> Allan Coleman
>>
>> __________________________________________________________
>>
>> Public Seismic Network Mailing List (PSN-L)
>>
>> To leave this list email PSN-L-REQUEST@.............. with
>> the body of the message (first line only): unsubscribe
>> See http://www.seismicnet.com/maillist.html for more information.
>>
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Publication on the Web
From: ChrisAtUpw@.......
Date: Sat, 17 Nov 2001 19:48:43 EST
In a message dated 17/11/2001, jimesler@.......... writes:
> Does anyone have any experiences in building an inferometer for measuring
> displacement in seismographs?
> Jim Esler
Dear Jim Esler,
The problem with using methods which depend on the wavelength of light
is that you are ultimately limited by this dimension, which is about 0.6
micron. When observing seismic signals, you will probably want a resolution
of better than 1/20 of this. While optical sensors which measure to small
fractions of a wavelength can be bought, they are neither simple nor cheap.
The wavelength limitation may be largely avoided by using a fairly
intense and constant light source to illuminate a pair of silicon
photodiodes through a moving shutter attached to the seismometer arm. The
difference in the photocurrents is measured, filtered and amplified. This
'photon counting' method is also simpler in principle than interferometer
techniques. Hope that this helps.
Regards,
Chris Chapman
<HTML><FONT FACE=arial,helvetica><FONT SIZE=2>In a message dated 17/11/2001, jimesler@.......... writes:
<BR>
<BR><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Does a
nyone have any experiences in building an inferometer for measuring
<BR>displacement in seismographs?
<BR>Jim Esler</FONT><FONT COLOR="#000000" SIZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG="0"></BLOCKQUOTE>
<BR></FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">
<BR>Dear Jim Esler,
<BR>
<BR> The problem with using methods which depend on the wavelength of light is that you are
ultimately limited by this dimension, which is about 0.6 micron. When observing seismic signals, you will probably want a reso
lution of better than 1/20 of this. While optical sensors which measure to small fractions of a wavelength can be bought, they
are neither simple nor cheap.
<BR>
<BR> The wavelength limitation may be largely avoided by using a fairly intense and c
onstant light source to illuminate a pair of silicon photodiodes through a moving shutter attached to the seismometer arm. The
difference in the photocurrents is measured, filtered and amplified. This 'photon counting' method is also simpler in principle
than interferometer techniques. Hope that this helps.
<BR>
<BR> Regards,
<BR>
<BR> Chris Chapman </FONT
></HTML>
Subject: AD board
From: "Bryan&Regina Goss" bgoss@..................
Date: Mon, 19 Nov 2001 12:50:11 -0600
I have an extra 16 Bit PSN-ADC version (Rev 2 board see =
http://www.seismicnet.com/atod.html for more info this is a real deal I =
bought 2 boards I only need one I paid $230 I will sell it for $150 it =
is in perfect working order and comes with connector cables already =
assembled. you can reply to the list or bgoss@.................. I have =
an ebay paypal account if you wish to pay that way or Check, Money =
Order.=20
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content=3D"text/html; charset=3Diso-8859-1" =
http-equiv=3DContent-Type>
<META content=3D"MSHTML 5.00.2919.6307" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff><FONT face=3DArial size=3D2>I have an extra 16 =
Bit PSN-ADC=20
version (Rev 2 board see <A=20
href=3D"http://www.seismicnet.com/atod.html">http://www.seismicnet.com/at=
od.html</A> for=20
more info this is a real deal I bought 2 boards I only need one I paid =
$230 I=20
will sell it for $150 it is in perfect working order and comes with =
connector=20
cables already assembled. you can reply to the list or <A=20
href=3D"mailto:bgoss@..................">bgoss@..................</A> I =
have an=20
ebay paypal account if you wish to pay that way or Check, Money Order.=20
</FONT></BODY></HTML>
Subject: AD board
From: "Bryan&Regina Goss" bgoss@..................
Date: Mon, 19 Nov 2001 14:07:47 -0600
I have the AD board Sold that I posted if not I will repost it
Thanks........... Bryan
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Publication on the Web
From: "jimesler" jimesler@..........
Date: Tue, 20 Nov 2001 23:40:29 -0600
Hello,
Thanks for the pointers with the PDF file.=20
Thanks for the tip - I've been playing around with a Texas Instruments =
TSL230 chip - http://www.taosinc.com/pdf/tsl230.pdf which is a light to =
frequency converter - which if you have enough time between samples may =
possibly be used as a photon counter???. One of the problems in using =
an inferometer outside of the resolution issue is that the arc of the =
boom would tend to throw the alignment required out of line. =20
I saw really neat web page @ =
http://www.users.globalnet.co.uk/~blootl/trackers/sunflower.htm - some =
folk in the U.K. have been constructing very large parabolic mirror to =
point at the sun, > 40 KW outputs... The TSL230 would make for a =
dandy solar alignment sensor.
Here on the tundra of Minnesota, I've just built my second 24 bit ADC =
board - sent it off to my brother in Canada for eval. I'm using a 30K =
turn coil and a (1,10,100,1000 x ) programmable gain amp - and a stamp =
to control it all - sending 10 hz data to my PC with a VB front end that =
displays my traces in realtime.... I get quite a signal just rotating =
the assemby away from any magnet - just using the earth magnetic feild =
to interact with the coil... The whole thing sits on a 2 x 3 inch board =
running of a single sided supply. I steal a +12 v line from the PC to =
run it.
Jim
----- Original Message -----=20
From: ChrisAtUpw@..........
To: psn-l@.................
Sent: Saturday, November 17, 2001 6:48 PM
Subject: Re: Publication on the Web
In a message dated 17/11/2001, jimesler@.......... writes:=20
Does anyone have any experiences in building an inferometer for =
measuring=20
displacement in seismographs?=20
Jim Esler
Dear Jim Esler,=20
The problem with using methods which depend on the wavelength of =
light is that you are ultimately limited by this dimension, which is =
about 0.6 micron. When observing seismic signals, you will probably want =
a resolution of better than 1/20 of this. While optical sensors which =
measure to small fractions of a wavelength can be bought, they are =
neither simple nor cheap.=20
The wavelength limitation may be largely avoided by using a =
fairly intense and constant light source to illuminate a pair of =
silicon photodiodes through a moving shutter attached to the seismometer =
arm. The difference in the photocurrents is measured, filtered and =
amplified. This 'photon counting' method is also simpler in principle =
than interferometer techniques. Hope that this helps.=20
Regards,=20
Chris Chapman =20
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content=3D"text/html; charset=3Diso-8859-1" =
http-equiv=3DContent-Type>
<META content=3D"MSHTML 5.00.2614.3500" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT size=3D2>Hello,</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=3D2>Thanks for the pointers with the PDF file. =
</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=3D2>Thanks for the tip - I've been playing around with a =
Texas=20
Instruments TSL230 chip - <A=20
href=3D"http://www.taosinc.com/pdf/tsl230.pdf">http://www.taosinc.com/pdf=
/tsl230.pdf</A> =20
which is a light to frequency converter - which if you have enough time =
between=20
samples may possibly be used as a photon counter???. One of the =
problems=20
in using an inferometer outside of the resolution issue is that the arc =
of the=20
boom would tend to throw the alignment required out of line. =
</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>I saw really neat web page @ <A=20
href=3D"http://www.users.globalnet.co.uk/~blootl/trackers/sunflower.htm">=
http://www.users.globalnet.co.uk/~blootl/trackers/sunflower.htm</A> =
-=20
some folk in the U.K. have been constructing very large parabolic mirror =
to=20
point at the sun, > 40 KW outputs... The TSL230 would =
make for a=20
dandy solar alignment sensor.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=3D2>Here on the tundra of Minnesota, I've just built my =
second 24=20
bit ADC board - sent it off to my brother in Canada for eval. I'm =
using a=20
30K turn coil and a (1,10,100,1000 x ) programmable gain amp - and a =
stamp to=20
control it all - sending 10 hz data to my PC with a VB front end that =
displays=20
my traces in realtime.... I get quite a signal just rotating the =
assemby=20
away from any magnet - just using the earth magnetic feild to interact =
with the=20
coil... The whole thing sits on a 2 x 3 inch board running of a =
single=20
sided supply. I steal a +12 v line from the PC to run =
it.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=3D2>Jim</FONT></DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>----- Original Message ----- </DIV>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: =
0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px">
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A href=3D"mailto:ChrisAtUpw@......."=20
title=3DChrisAtUpw@.......>ChrisAtUpw@.......</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
href=3D"mailto:psn-l@.............."=20
title=3Dpsn-l@..............>psn-l@..............</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Saturday, November 17, =
2001 6:48=20
PM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: Publication on the =
Web</DIV>
<DIV><BR></DIV><FONT face=3Darial,helvetica><FONT size=3D2>In a =
message dated=20
17/11/2001, <A =
href=3D"mailto:jimesler@..........">jimesler@..........</A>=20
writes: <BR><BR>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; =
MARGIN-RIGHT: 0px; PADDING-LEFT: 5px"=20
TYPE=3D"CITE">Does anyone have any experiences in building an =
inferometer for=20
measuring <BR>displacement in seismographs? <BR>Jim =
Esler</FONT><FONT=20
color=3D#000000 face=3DArial lang=3D0 size=3D3=20
FAMILY=3D"SANSSERIF"></BLOCKQUOTE><BR></FONT><FONT color=3D#000000 =
face=3DArial=20
lang=3D0 size=3D2 FAMILY=3D"SANSSERIF"><BR>Dear Jim Esler,=20
<BR><BR> The problem with using =
methods=20
which depend on the wavelength of light is that you are ultimately =
limited by=20
this dimension, which is about 0.6 micron. When observing seismic =
signals, you=20
will probably want a resolution of better than 1/20 of this. While =
optical=20
sensors which measure to small fractions of a wavelength can be =
bought, they=20
are neither simple nor cheap. =
<BR><BR> The=20
wavelength limitation may be largely avoided by using a fairly intense =
and=20
constant light source to illuminate a pair of silicon =
photodiodes=20
through a moving shutter attached to the seismometer arm. The =
difference in=20
the photocurrents is measured, filtered and amplified. This 'photon =
counting'=20
method is also simpler in principle than interferometer techniques. =
Hope that=20
this helps. <BR><BR> Regards,=20
<BR><BR> Chris Chapman=20
=
</FONT>=
=20
</FONT></BLOCKQUOTE></BODY></HTML>
Subject: Re: Publication on the Web
From: ChrisAtUpw@.......
Date: Thu, 22 Nov 2001 17:08:11 EST
In a message dated 21/11/2001, jimesler@.......... writes:
> I've been playing around with a Texas Instruments TSL230 chip - <A HREF="http://www.taosinc.com/pdf/tsl230.pdf">
> http://www.taosinc.com/pdf/tsl230.pdf</A> which is a light to frequency
> converter - which if you have enough time between samples may possibly be
> used as a photon counter?
Dear Jim Esler,
I looked at the TSL230 data sheet and I am doubtful if it could give
the very high resolution required for a seismometer. If you want to try a
photo detector system, I suggest that you experiment with a couple of the 7.5
sqmm photodiodes type VTD34 from www.newark.com. Illuminate them from a
common source, preferably a filament lamp run at about 3/4 the rated voltage,
to give a half shaded current of 50 to 100 micro A each.
Regards,
Chris Chapman
<HTML><FONT FACE=arial,helvetica><FONT SIZE=2>In a message dated 21/11/2001, jimesler@.......... writes:
<BR>
<BR><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px"> I've
been playing around with a Texas Instruments TSL230 chip - <A HREF="http://www.taosinc.com/pdf/tsl230.pdf">http://www.taosinc.c
om/pdf/tsl230.pdf</A> which is a light to frequency converter - which if you have enough time between samples may possibl
y be used as a photon counter?</FONT><FONT COLOR="#000000" SIZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG="0"></BLOCKQUOTE>
<BR>
<BR></FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">Dear Jim Esler,
<BR>
<BR> I looked at the TSL230 data sheet and I am doubtful if it could give the very high res
olution required for a seismometer. If you want to try a photo detector system, I suggest that you experiment with a couple of
the 7.5 sqmm photodiodes type VTD34 from www.newark.com. Illuminate them from a common source, preferably a filament lamp run a
t about 3/4 the rated voltage, to give a half shaded current of 50 to 100 micro A each.
<BR>
<BR> Regards,
<BR>
<BR> Chris Chapman</FONT></HTML>
Subject: System problems
From: "Larry Cochrane" cochrane@..............
Date: Sat, 24 Nov 2001 16:06:23 -0800
All,
This list and my web site will be intermittent for the next few days. A
large storm came through causing a big branch of a tree to brake off knock
out power in the area. I'm currently on a backup generator. Even though
there are telephone wires down on the ground one of my DSL lines is still
working. Since the generator, a Honda EU2000, is a little noisy I can't keep
it running all of the time. They are working on the lines now but it may
take a day or two before power is restored.
-Larry Cochrane
Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: RE: Publication on the Web
From: Jack Ivey ivey@..........
Date: Mon, 26 Nov 2001 10:35:17 -0500
Chris,
Just curious, why an incandescent bulb and not an LED? Also,
that's a pretty large area photodiode. Trying to keep the noise
down?
Thanks,
Jack Ivey
-----Original Message-----
From: ChrisAtUpw@....... [mailto:ChrisAtUpw@........
Sent: Thursday, November 22, 2001 5:08 PM
To: psn-l@..............
Subject: Re: Publication on the Web
In a message dated 21/11/2001, jimesler@.......... writes:
I've been playing around with a Texas Instruments TSL230 chip -
http://www.taosinc.com/pdf/tsl230.pdf
<http://www.taosinc.com/pdf/tsl230.pdf> which is a light to frequency
converter - which if you have enough time between samples may possibly be
used as a photon counter?
Dear Jim Esler,
I looked at the TSL230 data sheet and I am doubtful if it could give
the very high resolution required for a seismometer. If you want to try a
photo detector system, I suggest that you experiment with a couple of the
7.5 sqmm photodiodes type VTD34 from www.newark.com. Illuminate them from a
common source, preferably a filament lamp run at about 3/4 the rated
voltage, to give a half shaded current of 50 to 100 micro A each.
Regards,
Chris Chapman
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<META content="MSHTML 5.50.4522.1800" name=GENERATOR></HEAD>
<BODY>
<DIV><SPAN class=921101815-26112001><FONT face=Arial color=#0000ff
size=2>Chris,</FONT></SPAN></DIV>
<DIV><SPAN class=921101815-26112001><FONT face=Arial color=#0000ff size=2>Just
curious, why an incandescent bulb and not an LED? </FONT></SPAN><SPAN
class=921101815-26112001><FONT face=Arial color=#0000ff size=2>Also,
</FONT></SPAN></DIV>
<DIV><SPAN class=921101815-26112001><FONT face=Arial color=#0000ff size=2>that's
a pretty large area </FONT></SPAN><SPAN class=921101815-26112001><FONT
face=Arial color=#0000ff size=2>photodiode. Trying to </FONT></SPAN><SPAN
class=921101815-26112001><FONT face=Arial color=#0000ff size=2>keep
the noise </FONT></SPAN></DIV>
<DIV><SPAN class=921101815-26112001><FONT face=Arial color=#0000ff
size=2>down?</FONT></SPAN></DIV>
<DIV><SPAN class=921101815-26112001><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=921101815-26112001><FONT face=Arial color=#0000ff
size=2>Thanks,<BR>Jack Ivey</FONT></SPAN></DIV>
<DIV><SPAN class=921101815-26112001></SPAN><FONT face=Tahoma><FONT size=2><SPAN
class=921101815-26112001><FONT face=Arial
color=#0000ff> </FONT></SPAN></FONT></FONT></DIV>
<DIV><FONT face=Tahoma><FONT size=2><SPAN
class=921101815-26112001> </SPAN>-----Original Message-----<BR><B>From:</B>
ChrisAtUpw@....... [mailto:ChrisAtUpw@........<BR><B>Sent:</B> Thursday,
November 22, 2001 5:08 PM<BR><B>To:</B> psn-l@..............<BR><B>Subject:</B>
Re: Publication on the Web<BR><BR></DIV></FONT></FONT>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px solid"><FONT
face=arial,helvetica><FONT size=2>In a message dated 21/11/2001,
jimesler@.......... writes: <BR><BR>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px solid; MARGIN-RIGHT: 0px"
TYPE="CITE">I've been playing around with a Texas Instruments TSL230 chip -
<A
href="http://www.taosinc.com/pdf/tsl230.pdf">http://www.taosinc.com/pdf/tsl230.pdf</A>
which is a light to frequency converter - which if you have enough
time between samples may possibly be used as a photon counter?</FONT><FONT
lang=0 face=Arial color=#000000 size=3
FAMILY="SANSSERIF"></BLOCKQUOTE><BR><BR></FONT><FONT lang=0 face=Arial
color=#000000 size=2 FAMILY="SANSSERIF">Dear Jim Esler,
<BR><BR> I looked at the TSL230 data sheet
and I am doubtful if it could give the very high resolution required for a
seismometer. If you want to try a photo detector system, I suggest that you
experiment with a couple of the 7.5 sqmm photodiodes type VTD34 from
www.newark.com. Illuminate them from a common source, preferably a filament
lamp run at about 3/4 the rated voltage, to give a half shaded current of 50
to 100 micro A each.
<BR><BR> Regards,
<BR><BR> Chris Chapman</FONT>
</FONT></BLOCKQUOTE></BODY></HTML>
Subject: Re: Publication on the Web
From: ChrisAtUpw@.......
Date: Mon, 26 Nov 2001 21:49:44 EST
In a message dated 26/11/2001, ivey@.......... writes:
> Chris,
> Just curious, why an incandescent bulb and not an LED? Also, that's a
> pretty large area photodiode. Trying to keep the noise down?
> Thanks,
> Jack Ivey
Dear Jack Ivey,
The movement signal is proportional to the photodiode current. The
noise is proportional to the square root of the photo current, so you need as
large a photo current as is practicable to optimise the resolution (100 micro
Amp?). (Phototransistors amplify the noise as well as the signal and are NOT
useful here).You need physically fairly large, high sensitivity photodiodes,
well matched for response eg the VTD34. These allow an accurate linear
response for movements up to +/- 1 mm. The high Infra Red sensitivity of
Silicon photocells matches tungsten filament lamps very nicely.
Tungsten filament lamps can provide the fairly high light levels with
ease and the output can be very highly stabilised using a bridge circuit or
another Si photocell. A thin straight filament is ideal for the purpose. The
photon output is not effected by high frequency noise in the supply current.
If you reduce the supply voltage to about 3/4 the rated value, you get
effectively infinite filament life.
LEDs have four major disadvantages. The output decreases exponentially
with increasing temperature and the sensitivity is high - the chip
temperature needs to be closely regulated / compensated. LEDs have higher
inherent photon noise levels than tungsten filaments, with red LEDs being the
worst. The IR LEDs are fairly quiet. Any noise on the supply current appears
in the photon output. Most higher power LEDs have a cup like structure
surrounding the chip and a circular metal central contact area, which blocks
much radiation. It is usually not possible to get an effective 'point' source
- you see a central spot surrounded by a bright ring. The LID chip LEDs do
not have this problem, but are of lower power. High power regulated
specialist devices similar to laser diodes are available - Hamamatsu make a
nice one for ~$200. Laser diodes themselves are extremely noisy.
Regards,
Chris Chapman
<HTML><FONT FACE=arial,helvetica><FONT SIZE=2>In a message dated 26/11/2001, ivey@.......... writes:
<BR>
<BR></FONT><FONT COLOR="#0000ff" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0"><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #00
00ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Chris,</FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANS
SERIF" FACE="Arial" LANG="0">
<BR></FONT><FONT COLOR="#0000ff" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">Just curious, why an incandescent bulb and no
t an LED? Also, that's a pretty large area photodiode. Trying to keep the noise down?</FONT><FONT COLOR="#000000"
SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">
<BR> </FONT><FONT COLOR="#0000ff" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">Thanks,
<BR>Jack Ivey</FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0"></BLOCKQUOTE>
<BR>
<BR>Dear Jack Ivey,
<BR>
<BR> The movement signal is proportional to the photodiode current. The noise is proportion
al to the square root of the photo current, so you need as large a photo current as is practicable to optimise the resolution (
100 micro Amp?). (Phototransistors amplify the noise as well as the signal and are NOT useful here).You need physically fairly
large, high sensitivity photodiodes, well matched for response eg the VTD34. These allow an accurate linear response for moveme
nts up to +/- 1 mm. The high Infra Red sensitivity of Silicon photocells matches tungsten filament lamps very nicely.
<BR>
<BR> Tungsten filament lamps can provide the fairly high light levels with ease and the out
put can be very highly stabilised using a bridge circuit or another Si photocell. A thin straight filament is ideal for the pur
pose. The photon output is not effected by high frequency noise in the supply current. If you reduce the supply voltage to abou
t 3/4 the rated value, you get effectively infinite filament life.
<BR>
<BR> LEDs have four major disadvantages. The output decreases exponentially with increasing
temperature and the sensitivity is high - the chip temperature needs to be closely regulated / compensated. LEDs have higher i
nherent photon noise levels than tungsten filaments, with red LEDs being the worst. The IR LEDs are fairly quiet. Any noise on
the supply current appears in the photon output. Most higher power LEDs have a cup like structure surrounding the chip and a ci
rcular metal central contact area, which blocks much radiation. It is usually not possible to get an effective 'point' source -
you see a central spot surrounded by a bright ring. The LID chip LEDs do not have this problem, but are of lower power. High p
ower regulated specialist devices similar to laser diodes are available - Hamamatsu make a nice one for ~$200. Laser diodes the
mselves are extremely noisy.
<BR>
<BR> Regards,
<BR>
<BR> Chris Chapman</FONT></HTML>
Subject: WinSDR beta testers needed
From: "Larry Cochrane" cochrane@..............
Date: Wed, 28 Nov 2001 22:03:09 -0800
All,
I'm looking for a few beta testers to test my new WinSDR program. WinSDR is
a Windows based datalogger based on my SDR program. To run WinSDR you will
need two computers. Unfortunately it is not practical to write a device
driver for my ISA A/D card and still keep all of the functionality of SDR.
One computer would run a new version of SDR that only collects the data from
the A/D board, buffers and formats the data into packets and then sends the
packet out the serial port once a second. This program is called SDR Server
(the actual exe name is sdrservr.exe) and it must run under DOS. It has no
user interface nor does it display any data, just some status information so
that you know its working correctly.
Recently I tried a free version of DOS called OpenDOS. You can download it
here http://www.planetmirror.com/pub/drdos/OpenDOS.701/. It's working fine
with SDR Server and I assume it would also work with SDR. Since SDR Server
does not save any data except for a small ini file, you can create a DOS or
OpenDOS floppy boot disk and run SDR Server for a floppy.
WinSDR runs under Windows and uses one of the system's comm ports to
communicate to SDR Server or a new standalone A/D board that I am now ready
to sell. I don't have a web page setup for it yet but I do have a picture of
it here http://www.seismicnet.com/adserial_small.jpg. I designed this board
so new users won't need to run two computer systems. The board has a 16 bit
A/D chip and a microprocessor board on it made by Z-World. More info on the
module I am using can be found here
http://www.zworld.com/products/rcm2000/index.html. The model number is
RCM2020.
WinSDR currently has two windows. One is the main real-time display. This
window looks more or less like the main display in SDR. The other window is
used to replay and extract event files from the daily record files similar
to replaying data in SDR.
If you would like to be a beta tester please send me email and I will send
you a copy of WinSDR and SDR Server. I will also place you on a WinSDR beta
tester mailing list. Since at this point I have no documentation on WinSDR I
will use this list to explain the features in WinSDR etc. Beta testers can
use this mailing list to report bugs and ask questions related to WinSDR.
Regards,
Larry Cochrane
Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: WinSDR beta testers needed
From: "Mauro Mariotti" mariottim@............
Date: Thu, 29 Nov 2001 15:46:51 +0100
Larry,
if you give us the protocol of data transfer someone could
use a software that randomly generate data to test winsdr.
I could apply it for my serial card and test it.
I collected a bit of experience in serial comm and seismic recording
feel free to use my support.
Unfortunately at moment i have no isa card here to use like you suggest.
Mauro
----- Original Message -----
From: "Larry Cochrane" <cochrane@..............>
To: <psn-l@..............>
Sent: Thursday, November 29, 2001 7:03 AM
Subject: WinSDR beta testers needed
> All,
>
> I'm looking for a few beta testers to test my new WinSDR program. WinSDR
is
> a Windows based datalogger based on my SDR program. To run WinSDR you will
> need two computers. Unfortunately it is not practical to write a device
> driver for my ISA A/D card and still keep all of the functionality of SDR.
> One computer would run a new version of SDR that only collects the data
from
> the A/D board, buffers and formats the data into packets and then sends
the
> packet out the serial port once a second. This program is called SDR
Server
> (the actual exe name is sdrservr.exe) and it must run under DOS. It has no
> user interface nor does it display any data, just some status information
so
> that you know its working correctly.
>
> Recently I tried a free version of DOS called OpenDOS. You can download
it
> here http://www.planetmirror.com/pub/drdos/OpenDOS.701/. It's working fine
> with SDR Server and I assume it would also work with SDR. Since SDR Server
> does not save any data except for a small ini file, you can create a DOS
or
> OpenDOS floppy boot disk and run SDR Server for a floppy.
>
> WinSDR runs under Windows and uses one of the system's comm ports to
> communicate to SDR Server or a new standalone A/D board that I am now
ready
> to sell. I don't have a web page setup for it yet but I do have a picture
of
> it here http://www.seismicnet.com/adserial_small.jpg. I designed this
board
> so new users won't need to run two computer systems. The board has a 16
bit
> A/D chip and a microprocessor board on it made by Z-World. More info on
the
> module I am using can be found here
> http://www.zworld.com/products/rcm2000/index.html. The model number is
> RCM2020.
>
> WinSDR currently has two windows. One is the main real-time display. This
> window looks more or less like the main display in SDR. The other window
is
> used to replay and extract event files from the daily record files similar
> to replaying data in SDR.
>
> If you would like to be a beta tester please send me email and I will send
> you a copy of WinSDR and SDR Server. I will also place you on a WinSDR
beta
> tester mailing list. Since at this point I have no documentation on WinSDR
I
> will use this list to explain the features in WinSDR etc. Beta testers can
> use this mailing list to report bugs and ask questions related to WinSDR.
>
> Regards,
> Larry Cochrane
> Redwood City, PSN
>
>
>
>
>
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: WinSDR beta testers needed
From: "Mauro Mariotti" mariottim@............
Date: Thu, 29 Nov 2001 19:51:16 +0100
Hi all,
i just received a mail from PSN mailing list with object
about the WinSDR, this mail contains a virus.
I'll try to identify it but it seems to be similar to one
affected many computers here in Italy.
I'll keep you informed
the sender was
_morris@.......
but surely he is not responsible it is a virus
that email itself with an object theme that often has sense for
the receiver.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: WinSDR Beta
From: "Larry Cochrane" cochrane@..............
Date: Thu, 29 Nov 2001 13:36:49 -0800
Hi Jack,
Sorry, WinSDR will only work with my standalone A/D board or using the SDR
Server program on a DOS system. To run WinSDR, the A/D board must supply
more information then just the A/D data. Included in the packets from the
A/D sub-system is time information needed to keep very accurate timing down
to a few milliseconds, if the user uses a time reference source like GPS or
WWV.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "Jack Ivey" <ivey@..........>
To: <cochrane@..............>
Sent: Thursday, November 29, 2001 6:21 AM
Subject: WinSDR Beta
> Hi Larry,
> I'm interested in trying out WinSDR. Right now
> I don't have one of the supported a/d boards, but
> I have an a/d card with a serial output. I would
> like to make the changes to my firmware on that board
> so that it puts out the right format to be read
> with WinSDR. Is the format published?
>
> Thanks,
> Jack Ivey
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Virus Warning
From: "Larry Cochrane" cochrane@..............
Date: Thu, 29 Nov 2001 14:44:58 -0800
Mauro and others,
I don't think you got it from the PSN-L list since attachments are block
from being sent out. If you think it is from the PSN-L list please forward
the email message to me directly AND please include the headers. The new
virus is called W32/BadTrans. I just received an email message from Lisa
Koenig who maintains the VOLCANO(at)asu.edu list regarding this virus/worm.
I'm including it in this message. I personally have been getting a lot of
email messages with this virus in it. I must be in a lot of please address
book... I now use Norton AntiVirus software that seems to work very well at
not allowing these type of virus from infecting my system.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "Mauro Mariotti" <mariottim@............>
To: <psn-l@..............>
Sent: Thursday, November 29, 2001 10:51 AM
Subject: Re: WinSDR beta testers needed
> Hi all,
> i just received a mail from PSN mailing list with object
> about the WinSDR, this mail contains a virus.
> I'll try to identify it but it seems to be similar to one
> affected many computers here in Italy.
> I'll keep you informed
> the sender was
>
> _morris@.......
>
> but surely he is not responsible it is a virus
> that email itself with an object theme that often has sense for
> the receiver.
Hello volcano list subscribers,
Earlier this week I received multiple messages with attachments that
contained an e-mail virus (Badtrans). These messages were sent from the
accounts of a few list subscribers who had volcano e-mail from me in their
mailboxes, which made my address a target for the propagating virus.
Fortunately, neither I nor the volcano list was affected by these attacks.
In case you haven't heard about the Badtrans virus, you can get more
information at http://vil.mcafee.com/dispVirus.asp?virus_k=99069& or at
http://www.cert.org/incident_notes/IN-2001-14.html. I thought it also
would be useful to send out a general reminder about e-mail security, so
here are a couple of suggestions to help prevent the spread of e-mail
viruses:
1. Avoid opening e-mail attachments, regardless of the sender's name,
without prior knowledge of the origin of the file or a valid digital
signature, or without first saving the attachment and checking it with
anti-virus software. You should be especially careful if the attachment is
an executable program (.exe extension). Note that some viruses may be
labeled with other file extensions, but contain executable files.
2. Users of Microsoft Outlook or Outlook Express may be particularly
vulnerable to virus attacks, due to the tight integration of this software
with the Windows operating system. For example, the Badtrans virus is
capable of infecting your computer even if you do not open the virus
attachment, if you read the e-mail message in the preview mode of Outlook.
If you do use Outlook or Outlook Express as your e-mail program, visit the
Microsoft web site regularly to download and install new security patches.
If you'd like more information about viruses and computer security, there
are some useful websites, such as CERT (http://www.cert.org) and McAfee
(http://www.mcafee.com/).
By the way, if you send a message for distribution to the volcano list,
please send it as plain text and not as an attachment if possible.
Thanks for your attention,
Lisa Koenig
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Virus Warning
From: Doug Crice dcrice@............
Date: Thu, 29 Nov 2001 15:22:43 -0800
A little more advice--
1) Update your anti-virus software often. They seem to work by having a
data base of known viruses, and many viruses I get are less than 2 weeks
old.
2) The following extensions are all executable programs and can contain
virus.
..lnk
..pif
..exe
..vbs
..com
..exe
..bat
..co
A lot of the ones I get are disguised with familiar extensions near the
end, for example: nakedcoeds.jpg.pif (especially deceptive because
pif sounds like gif).
Sounds like an ordinary photo but is really a virus, not that I would
click on any such file.
Doug
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: RE: WinSDR Beta
From: steve hammond shammon1@.............
Date: Thu, 29 Nov 2001 21:02:23 -0800
This virus is about 4 weeks old. You need to update your Norton anti-virus
software right now... this is a very nasty virus-- I have attached the
Symantec flash below.
Steve Hammond PSN Aptos Ca.
From: NAV-Techinfo [mailto:es@.............
Sent: Tuesday, November 27, 2001 4:16 PM
To: NAV-TECHINFO-L@....................
Subject: Norton AntiVirus SupportNow! News Bulletin: Nov. 27, 2001
November 27, 2001
_____________________________
In this issue:
1. W32.Badtrans.B@mm
2. W32.Aliz.Worm
3. Feedback
4. Subscribing and unsubscribing
5. Disclaimer
_____________________________
NOTE: This is an outgoing email address. Please do not reply to this
email message. If you require assistance installing, configuring, or
troubleshooting a Symantec product, or you have a question for
Customer Service, please visit the Symantec Service & Support Web
site at the following address:
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Select your product and version and click Go.
To see an HTML version of this newsletter, please visit the following
Web site:
http://www.symantec.com/techsupp/vURL.cgi/navarc
_____________________________
1. W32.Badtrans.B@mm
W32.Badtrans.B@mm is a MAPI worm that emails itself out as a file
with one of several different names. This worm also creates a .dll in
the \Windows\System directory as Kdll.dll. It uses functions from
this .dll to log keystrokes. Virus definitions dated November 24,
2001 will detect this worm. For additional information, point your
Web browser to:
http://www.symantec.com/techsupp/vURL.cgi/nav108
_____________________________
2. W32.Aliz.Worm
W32.Aliz.Worm is a very simple SMTP mass-mailer worm. The worm
currently only replicates on Windows 9x computers. It does not seem
to spread on Windows NT platforms. The worm spreads by obtaining
email addresses from the Windows address book and sending itself to
those addresses. Virus definitions dated May 22, 2001 will detect
this worm.
When the worm arrives by email, the worm uses a MIME exploit that
allows the virus to be run just by reading or previewing the email.
Information on and a patch for this exploit can be found at
http://www.symantec.com/techsupp/vURL.cgi/nav110
For additional information, point your Web browser to:
http://www.symantec.com/techsupp/vURL.cgi/nav109
_____________________________
3. Feedback
Do you have feedback that can help us provide better products or
services? If so, we would really like to hear from you. Please visit
Symantec's suggestion box at the following Web site and let us know
what you are thinking:
http://www.symantec.com/feedback/
_______________________________
4. Subscribing or unsubscribing
If you would like to subscribe to other Symantec newsletters, please
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If you no longer want to receive this newsletter, let us know by
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If you would like to unsubscribe from other Symantec newsletters,
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_____________________________
5. Disclaimer
THIS DOCUMENT IS PROVIDED FOR INFORMATIONAL PURPOSES ONLY.
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-----Original Message-----
From: Larry Cochrane [SMTP:cochrane@...............
Sent: Thursday, November 29, 2001 1:37 PM
To: Jack Ivey
Cc: psn-l@..............
Subject: Re: WinSDR Beta
Hi Jack,
Sorry, WinSDR will only work with my standalone A/D board or using the SDR
Server program on a DOS system. To run WinSDR, the A/D board must supply
more information then just the A/D data. Included in the packets from the
A/D sub-system is time information needed to keep very accurate timing down
to a few milliseconds, if the user uses a time reference source like GPS or
WWV.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "Jack Ivey" <ivey@..........>
To: <cochrane@..............>
Sent: Thursday, November 29, 2001 6:21 AM
Subject: WinSDR Beta
> Hi Larry,
> I'm interested in trying out WinSDR. Right now
> I don't have one of the supported a/d boards, but
> I have an a/d card with a serial output. I would
> like to make the changes to my firmware on that board
> so that it puts out the right format to be read
> with WinSDR. Is the format published?
>
> Thanks,
> Jack Ivey
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Virus Warning / protocols
From: "Mauro Mariotti" mariottim@............
Date: Fri, 30 Nov 2001 09:27:57 +0100
I don't said that.
I simply advised the presence of a virus attachment for W32/BadTrans virus
that had as object: "WinSDR beta testers needed".
This mean that someone on the list has this virus and potentially can infect
others in the mailing list.
Sorry for my english maybe i expressed myself in a wrong way.
The removal of this virus is easy and it is described on the
www.symantec.com web site.
==========
About the protocol of the new card.
>Sorry, WinSDR will only work with my standalone A/D board or using the SDR
>Server program on a DOS system. To run WinSDR, the A/D board must supply
>more information then just the A/D data.
>Included in the packets from the A/D sub-system is time information needed
to keep very accurate timing down
>to a few milliseconds, if the user uses a time reference source like GPS or
WWV.
This mean do you prefer to do not publish the transfer protocol?
Warmly
Mauro
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Money
From: "Mauro Mariotti" mariottim@............
Date: Mon, 3 Dec 2001 22:17:50 +0100
Hi Larry,
today i sent 160 USD to you.
They should cover the 5 Winquake licenses,
one PCB of your a/d ISA card (and schematic)
and the mail charge to send the card to me.
Please send it as document in a letter like envelope.
I don't know how much was the mail charge i think it will be
less than 10$ for the remaining i'll enjoy to have offered you a pizza!
:-)
Warmly
Mauro
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Test
From: David Findlay david_j_findlay@............
Date: Tue, 4 Dec 2001 11:40:32 +1000
I haven't received the welcome message yet, but I'll assume this is working.
I'm in Brisbane Australia, and looking at building a Lehmann sensor because
it looks pretty easy to build.
I live about 400km from an tremor prone area, Bundaberg - Harvey Bay, the
most active in Australia according to a documentary I saw. I'd like to be
able to pick up stuff in that area, as well as around the rest of the world.
I was going to use timber to build my Lehmann unit with a dowel for the boom
and fishing line for the suspension of the boom. It will use a very strong
magnet for the pickup coil, and magnet horizontal damping at the end. I'll
likely align it north - south to pickup quakes in the region of interest. The
earthquakes around there are usually not what anyone really feels, but some
people occasionally do though. It will be in a small enclosure in the ground,
mounted on buried concrete besser blocks to hold it stable. The amp will be
in the pit, and then I'll have a cable running back to my house to where the
logging computer will be.
Is there anything I haven't thought of, and will this be able to do what I'm
interested in? In any case it will be a good easy one to start with. What
length pendulum should I use? Thanks,
David
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Test
From: ChrisAtUpw@.......
Date: Tue, 4 Dec 2001 11:27:08 EST
In a message dated 04/12/2001, david_j_findlay@............ writes:
> I'm in Brisbane Australia, and looking at building a Lehmann sensor because
> >
> I live about 400km from an tremor prone area, Bundaberg - Harvey Bay. I'd
> like to be able to pick up stuff in that area, as well as around the rest
> of the world.
> I was going to use timber to build my Lehmann unit with a dowel for the
> boom
> and fishing line for the suspension of the boom. It will use a very strong
> magnet for the pickup coil, and magnet horizontal damping at the end.
Hi there David,
I think that you are just inviting trouble with a wooden construction.
Even if you could get it to work, it won't be stable enough to stay in
adjustment. I suggest that you use metal to build the frame, a metal boom and
piano wire suspension. You can use slotted angle steel / aluminium or steel
water pipe or copper / stainless steel water pipe. With copper pipe you can
use soldered joints or compression fittings. With stainless steel you use
compression fittings. With galvanised steel, you need to be able to thread
the pipe and use threaded fittings. The bottom hinge joint on the boom can be
a ball bearing or a suspension wire. Suggest that you look around the psn.net
sites for photo examples.
> mounted on buried concrete
> besser blocks to hold it stable.
You would be much better casting a square / rectangular slab using a
cement and sand mixture, no gravel. This gives the least movement while the
mix cures slowly over some months. Make it about twice the dimensions of the
seis.
> Is there anything I haven't thought of, and will this be able to do what I'm
> interested in? What length pendulum should I use?
The old commercial seis used about 18" boom, but 12" seems OK. See
John Cole's mini Lehman.
Regards,
Chris Chapman
<HTML><FONT FACE=arial,helvetica><FONT SIZE=2>In a message dated 04/12/2001, david_j_findlay@............ writes:
<BR>
<BR><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">I'm in
Brisbane Australia, and looking at building a Lehmann sensor because
<BR>it looks pretty easy to build.</BLOCKQUOTE> <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN
-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">
<BR>I live about 400km from an tremor prone area, Bundaberg - Harvey Bay. I'd like to be able to pick up stuff in that area, as
well as around the rest of the world.
<BR>I was going to use timber to build my Lehmann unit with a dowel for the boom
<BR>and fishing line for the suspension of the boom. It will use a very strong
<BR>magnet for the pickup coil, and magnet horizontal damping at the end. </FONT><FONT COLOR="#000000" SIZE=3 FAMILY="SANSSERI
F" FACE="Arial" LANG="0"></BLOCKQUOTE>
<BR>
<BR>Hi there David,
<BR>
<BR></FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0"> I think
that you are just inviting trouble with a wooden construction. Even if you could get it to work, it won't be stable enough to s
tay in adjustment. I suggest that you use metal to build the frame, a metal boom and piano wire suspension. You can use slotted
angle steel / aluminium or steel water pipe or copper / stainless steel water pipe. With copper pipe you can use soldered join
ts or compression fittings. With stainless steel you use compression fittings. With galvanised steel, you need to be able to th
read the pipe and use threaded fittings. The bottom hinge joint on the boom can be a ball bearing or a suspension wire. Suggest
that you look around the psn.net sites for photo examples.
<BR> </FONT><FONT COLOR="#000000" SIZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG="0">
<BR></FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">It will be in a small enclosure in the ground
, <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">mounted
on buried concrete besser blocks to hold it stable. </FONT><FONT COLOR="#000000" SIZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG="
0"></BLOCKQUOTE>
<BR>
<BR></FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0"> You woul
d be much better casting a square / rectangular slab using a cement and sand mixture, no gravel. This gives the least movement
while the mix cures slowly over some months. Make it about twice the dimensions of the seis.
<BR></FONT><FONT COLOR="#000000" SIZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG="0">
<BR></FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0"><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #00
00ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Is there anything I haven't thought of, and will this b
e able to do what I'm interested in? What length pendulum should I use?</FONT><FONT COLOR="#000000" SIZE=3 FAMILY="SANSSERIF"
FACE="Arial" LANG="0"></BLOCKQUOTE>
<BR>
<BR></FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0"> The old
commercial seis used about 18" boom, but 12" seems OK. See John Cole's mini Lehman.
<BR></FONT><FONT COLOR="#000000" SIZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG="0">
<BR> </FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">Regards,
<BR>
<BR> Chris Chapman</FONT><FONT COLOR="#000000" SIZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG
="0">
<BR></FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">
<BR></FONT></HTML>