A rapid resistance measurement system for quartz pendulums

Abstract

A quartz pendulum, gold plated on both sides, is the core component of a quartz accelerometer. Currently, a two-wire manual measurement method is employed to measure the resistance at 24 key positions on the gold plating to evaluate manufacturing quality. This method is time-consuming and has poor repeatability. In this paper, an automatic measurement system is proposed to measure these 24 resistances. The proposed system consists primarily of a lab-designed holder that clamps the sample, a machine vision unit to measure the sample position, RXY-stages for precise positioning, two lab-designed probes with 48 needles to sense the electrical signals, a multichannel self-switching module to sample the electrical signals from the probe needles, and a 7½-digital multimeter to measure the resistances. In addition, a simple, precise pre-measurement positioning method is introduced here. Experimental results show that the quartz-pendulum resistances can be measured quickly and precisely using the proposed system. The measurement rate of 1 pendulum/min is a factor of 10 faster than the current manual method, the measurement stability error is only 0.9 mΩ (a relative error of 0.13%), and the measurement repeatability error is 1.2 mΩ (a relative error of 0.20%).