电阻箱零值电阻的误差分析

The Analysis of the Error of the Zero Resistance of the Resistance Box

电阻箱是电磁学实验中的重要实验器材．实验中，计算实验误差时常常不考虑电阻箱零值电阻所引起的误差．而实际上，存放一段时间的电阻箱其零值电阻将大大超过原来的额定零值电阻．用这些电阻箱去做实验时，会对实验数据正确性造成一定影响．在用电阻箱代替高值电阻时，其影响比较微小可以忽略，而用电阻箱代替低值电阻时，电阻箱零值电阻造成的误差是比较大的，所以在实验中就要对其进行测量并修正.为了使电阻箱保持比较正常的零值电阻，必须按照正确的方法来保存电阻箱．

A resistrance box is one of the most important instruments for physics experimentin electromagnetism. In expriments, we seldom consider the error caused by the zero resistance of a resistance box when we calculate the error of the expriments. As a matter of fact, the zero resistance of a resistance box which is kept for some tlme will surpass the orlginally specified zero resistance. When we do experiments with these resistance boxes, it will have great effect on the accuracy of the expriment data. When we use the resistance box with non-zero resistance to replace a high resistance, it will cause slight inaccuracy and we can neglect it, if we use the resistance box, in place of a resistance of low value, it will cause great error, so we have to measure and correct it. In order to keep the resistance box in appropriately normal zero resistance, we should preserve the resistance box in a correct way.