If you want a high quality vertical seismometer I suggest you think along
the line of a Force Balance Vertical (FBV) seismometer. See
https://sites.google.com/site/seismicsensorinfo/ as a starting point. There
are several people that have built these and are very open for support and
answer questions.
Gary







-----Original Message-----
From: psnlist-request@.............. [mailto:psnlist-request@...............
On Behalf Of tdavisjb
Sent: Thursday, November 17, 2011 9:37 PM
To: PSN Listserver
Subject: Spring for AS-1 type vertical seismometer

Folks,
I am building a vertical seismometer based on drawings put together by Kay
Wyatt (with help from Chris Chapman), it uses a piano wire hinge and the
coil is attached to the boom. My current problem is locating a spring for
this thing. I have found one at the local hardware store, it's long enough
(about 14") but it's pretty large in diameter and perhaps a bit too stiff. 
I have tried to contact Kay but have had no luck. I work in a middle school
here in Portland (I'm the tech support person) and we have 2 AS-1's that I
maintain. Their springs are much smaller in diameter. So I am wondering if
any one on the list knows where, or how I would go about obtaining such a
spring.
I might mention that I have built two horizontal seismometers based on  the
design that Chris Chapman helped to design in England for use in schools.
They use crossed carbide rods for hinges. I wound my own coils and hope to
have them up and recording within a year (being realistic here, as I have
been working on all three seismometers, on and off for almost a year
already). So I may be asking more questions!
Thanks in advance for any help. You can respond here or email me direct:
tdavisjb@............



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