热导式氢气纯度分析仪的设计

Design of Thermal Conductivity Method Hydrogen Concentration Detector

热导检测器是利用被测组分和参考气的热导系数不同而响应的浓度型检测器,是一种非破坏性检测器,可与其他检测器联用。本文介绍了一种利用热导检测器测量氢气纯度的方法,提出了热导式氢气纯度分析仪的总体设计方案。本设计的特点是将参考气(氮气)直接密封于热导检测器中,测量时不用再向仪器持续输入参考气,再利用数字温度传感器DS18B20检测温度,对恒流源及运放的温漂进行补偿。主要介绍了氢气热导池检测器、信号处理电路、键盘显示等电路的工作原理及部分程序的设计思想。并给出了样机的应用测试数据。

The Thermal Conductivity Detector（ TCD ） is concentration detector that measure the thermal conductivity coefficient of the sampled gas different from the reference gas,is a not destructiveness detector,can use with other detector. This disquisition introduced a way for measure the hydrogen concentration by the TCD,and bring up the total design project of thermal conductivity method hydrogen concentration detctor. The characteristics of this design is the reference gas （ nitrogen ） sealed inside of the TCD, need not input the reference gas to the TCD while measure,detect the temperature by digital sensor DS18B20 to compensate the temperature drift of the constant current regulator and amplifier. Introduced primarily the work principle about the TCD, signal handle circuit,keyboard circuit and display circuit etc,and design idea of part porgram. Give outed the data of application.