Ia. Bilenko et al., DEVICE FOR MEASURING THE OSCILLATION DECAY IN PENDULUMS WITH SMALL ENERGY DISSIPATIONS, Instruments and experimental techniques, 36(5), 1993, pp. 785-787
This paper describes a device which can measure pendulum-oscillation d
ecay times of the order of congruent-to 107 sec. This is the decay tim
e characteristic of pendulums produced entirely from high-quality fuse
d quartz. The decay time was derived from the change in the oscillatio
n amplitude measured by an optical pickup. Its operation is based on a
n amplitude-to-time conversion.