A High Speed Recorder for the GSI Pendulum Apparatus

Abstract

A new type high speed recorder for the GSI pendulum apparatus has been designed and constructed. The recorder consists of a crystal clock, a time-signal receiver, an amplifier, a spark chronograph with a power source and an optical device. Light signals from pendulums are transduced to electrical pulses, amplified and recorded by the spark chronograph. Periods of the pendulums are determined by comparing these signals with time marks of 1, 000 cycles per second given by the crystal clock or the JJY time signals. By this recorder, errors due to recording itself will be made less than 10^-7, much smaller than those due to the pendulum or any other origins . Therefore, it is expected that detailed knowledges about characteristics of the pendulums, especially of the knife-edge and the supporting plane, will be obtained and the accuracy of the gravity measurement may be ensured and even improved.