双电桥装置中灵敏电流计的选择方法

The Choice Method of Micro Detector in the Double Bridge Equipment

测量低电阻要用到双臂电桥,并且把被测电阻改为四端接法,在电路装置上采取措施,这样可以消除连接导线的电阻和接线柱的接触电阻的影响所带来的测量误差。所以双臂电桥测低电阻的主要误差来源是桥臂电阻的准确度和电桥的灵敏度。桥臂电阻的准确度等级目前可以做的很高,因此双电桥的灵敏度主要取决于电流计的灵敏度。本文讨论为了减小测量误差,对双臂电桥的灵敏电流计如何进行选择。

It can eliminate the measurement error from resistance of linking wire and contact resistance of of wiring terminal to measure low resistance by double bridge,change measured resistance to four essential points and take measures in circuit arrangement. So the source of governing error measuring low resistance by double bridge is from accuracy of bridge resistance and sensitivity of bridge. Accuracy grade of bridge resistance can be high,but sensitivity of bridge mainly lies on sensitivity of ampere meter.