Karl
   My problem with the leaf springs has been temporary creep(6 months+). I was
thinking of experimenting with  phosphor bronze as a spring material. I solved
the temperature problem by including a bimetal temp gauge coil. It took a
little iteration to find the location on the beam that compensated for the
temperature flucuations without over compensating.
Barry

Karl Cunningham wrote:

> 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@.......
>


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