超低霜点湿度发生器研制

Development of Ultra-low Frost Point Generator

基于双温双压法原理研制了一台超低霜点湿度发生器,发生霜点范围达到-110~-20℃。优化设计了饱和器和恒温设备等核心部件,并采用“蒸发”和“冷凝”两种模式验证了饱和器的饱和效率。在不同饱和温度和饱和压力条件下,分别采用冷镜式精密露点仪和光腔衰荡微量水分仪,与发生器进行了比对测试。试验结果表明:当霜点温度为-90℃时,露点仪与发生器偏差为0.02℃。当饱和压力为1 MPa、饱和温度为-99.60℃时,光腔衰荡微量水分仪与发生器的霜点温度偏差为0.04℃。对影响发生器测量结果的不确定度因素进行了不确定度评定。发生器在霜点温度-110℃、-90℃和-20℃时,扩展不确定度分别为0.40℃、0.20℃和0.19℃,k=2。

A novel ultra-low frost point generator(CIMM-TH)has been developed by using the two-temperature and two-pressure method in the frost point temperature range from -110℃ to -20℃.The core components of the saturator and thermostat were optimized,and the saturation efficiency of the saturator was verified by using two modes of“evaporation”and“condensation”.Under different saturation temperature and pressure conditions,a cold mirror precision dew-point meter and a micro-moisture meter were used to compare with the generator.The test results show that when the frost point temperature is -90℃,the deviation between the dew-point meter and the generator is 0.02℃.When the saturation pressure is 1 MPa and the saturation temperature is -99.60℃,the deviation of frost point temperature between the micro moisture meter and the generator is 0.04℃.The uncertainty factors affecting the measurement results of the generator are analyzed systematically.The expanded uncertainty of the generator is 0.38℃,0.20℃ and 0.19℃ at the frost point of -110℃,-90℃ and -20℃,respectively,k=2.