【摘要】 研究纳米材料内部结构和电阻输运机制需要有高精度的仪器来测量纳米材料的电阻率和磁阻．凯尔文直流双臂电桥和直流电位差计具有灵敏度高、读数精确和使用方便的特点，尤其是直流电位差计在使用时不影响被测对象的原来的状态，是精确测定纳米材料电阻率和磁阻的有效工具．本文介绍了它们的测量原理和方法以及在实际操作过程中要注意的一些问题更多还原

【Abstract】 High precision instruments of measuring electrical resistivity and magnetoresistivity are needed to study the inner structure and resistance characteristic of nanocrystalline materials. When applied, Kelvin bridge and potentiometer have the virtues of high sensitivity, precision reading and convenience to use, especially potentiometer does not affect the original state of the samples being detected at all. Both of them are effective tools to measure the electrical resistivity and magnetoresistivity precisely. Their principles and methods of measurement as well as some problems worthy of note in practice are introduced here.更多还原