In article ,
Jon Elson wrote:

Joseph Gwinn wrote:


The original Wyler unit (described in 4,023,413) may be made of fused
quartz, which would be easy for a big company like Wyler to do, but a
problem for me. I know how, but it would be far too much work. The
patent mentions quartz as a suitable material. So, the question is if
quartz is really necessary. Symmetry may suffice.

The Talyvel is housed in a cast aluminum frame,
with probably stainless parts inside holding the
platform. The platform can be tilted with two
micrometer knobs on top to compensate for
intentional tilt. When you screw them both down,
it locks the pendulum.

I assume that the foot is cast iron.

How sensitive is the unit to magnetic fields?

Are there any patent numbers on the unit or in its documentation?


I think fused silica is totally insane, the
thermal drift of my unit is really quite small.

Swiss precision! Must be zero drift!

Actually, making something out of fused quartz and invar is easy for an
optics shop, and the Wyler tilt sensor has only three parts requiring no
adjustments, so it may well be cheaper to make than the Taylvel sensor
unit.

Joe Gwinn