防尘过滤器对湿敏电容传感器低温使用的影响

Effect of Membrane Filter on Use for Humidity Capacitor at Lower Temperature

我部用 ＢＳＦ—ＱＤＩ型标准湿度发生装置对从芬兰引进的 ＨＭＰ４５Ｄ型湿敏电容传感 器进行了２０℃和－３０℃温度条件下的测试，测试中发现不仅两种温度条件下时间常数有很 大差异，而且在－３０℃时该湿敏电容传感器的防尘过滤器对其时间常数和测量误差有较大 影响。本文根据湿敏电容传感器的结构特点，依据试验结果，经进一步试验和分析，找到了产 生的原因和解决的办法。

We have tested model HMP 45D humidity capacitor sensors by model BSF - QDI standard humidity generator at 20℃ and - 30 ℃. These sensors are imported from Finland. In test, we found not only time constant is very different at the two temperature, but also the membrane filter of this model humidity capacitor sensor effects time constant and error of measurement greatly at - 30 ℃. In this text, according to structure character of humidity capacitor sensor and test result, we have found the reason and solving method by further test and analysis.