内燃机车热平衡试验时,需要测定柴油机、中冷器、热交换器、散热器等进口与出口的水或油的温差。由于所测温差值较小(2～10℃),精度要求较高(准确到0.1度),过去一般采用二级以上精度的玻璃水银温度计测量。虽然能满足试验要求,但需投入较多的试验记录人员,观察及读数不方便,工作条件较差。近年来,由于数字式仪表及自动打印记录 Diesel locomotive thermal balance test, you need to determine the diesel engine, intercooler, heat exchangers, radiators and other import and export of water or oil temperature difference. As the measured temperature difference is small (2 ~ 10 ℃), higher accuracy (accurate to 0.1 degrees), the past generally used two or more precision glass mercury thermometer measurements. Although able to meet the test requirements, but need to invest more test record staff, observation and reading inconvenient, poor working conditions. In recent years, due to digital instrumentation and automatic print records