用板式电位差计测干电池内阻时附加的标准电阻取值大小分析简

分析标准电阻取值大小对测量可能产生的影响。若标准电阻取值太大，测量线路的灵敏度将降低，同时标准电阻真实值相对额定值的差异对测量结果的影响也变大；若标准电阻取值太小，流过于电池的电流变大，于电池内部极化会使干电池内阻增大。实测结果也支持上述分析。

Determine the Range of a Subsidiary Standard Resistance for the Experiment of Measuring a Cell＇s Internal Resistance Using a Board Potentiometer

Several effects of the value of the standard resistance upon measuring result are studied. With higher value of the standard resistance, sensitivity of the circuit would become lower, and difference between real value and rated value of the standard resistance would have more influence on meas-uring result. With lower value of the standard resistance, current flowing over the cell would become higher,consequently higher electric susceptibility inside the cell enlarging value of the cell＇s internal resistance. The outcomes are sustained by measuring results.