Greg --

I would love to find some leaf spring material that is non-magnetic and has
near zero temperature coefficients of both linear expansion and modulus of
elasticity (the latter two may sort-of go together, metalurgically).  I'm
sure such alloys exist for the escapement springs of watches and clocks,
not to mention commercially-made seismometers.  I haven't checked, but I
imagine the cost would be high for enough material to build a seismometer
similar to Sean-Thomas'.

Karl Cunningham
La Mesa, CA.
PSN Station #40
karlc@.......


At 03:01 PM 8/3/99 -0700, you wrote:
>A while back there was a discussion about spring material for home built
>instruments. I can't remember if anyone ever found something decent for
>a reasonable price. Sean-Thomas' email about the geophone broad band
>mass made me wonder why not just make your own? Does $1000 seem like a
>reasonable price for a 1 Hz geophone, when you can get a 4.5 Hz for $60?
>Maybe we could bypass some of that cost? I know the spring in a geophone
>is pretty fancy for home builders, but maybe something simpler would
>work almost as good?


_____________________________________________________________________

Public Seismic Network Mailing List (PSN-L)