ND5型机车在我国运用已近10年，电机速度传感器受振动和温度变化的影响较大，内部部分元器件已经老化，有的焊点出现虚按现象。这些因素都会造成传感器不能正常工作，影响机车的正常运行，仅去年一年我段就因速度传感器故障而造成机破12件，占机破总件数的11％。但大多数传感器 ND5 locomotive has been used in our country for nearly 10 years. The motor speed sensor is greatly affected by the vibration and temperature changes. The internal components have been aged, and some of the solder joints have the phenomenon of virtual press. These factors will cause the sensor can not work properly, affecting the normal operation of the locomotive, the last year alone because of the speed sensor fault caused 12 broken machine, accounting for 11% of the total number of broken machine. But most sensors