[time-nuts] Sensing pendulum position, speed, or height
Dr Bruce Griffiths
bruce.griffiths at xtra.co.nz
Thu May 31 21:18:32 EDT 2007
Tom Van Baak wrote:
> A Measurement of the Period Stability of a Free Pendulum
> Clever solution. His optical gap is something like 5 microns.
An additional issue is the pointing instability of the laser used.
A position sensitive detector (lateral-effect photodiode sensor) for
which the output is independent of the beam flux could be used however
the noise and drift (typically <=1um/C) may be an issue.
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