气体传感器的动态高精度测试系统设计

Design of a dynamic high-precision characterizing system for gas sensors

目前气体传感动态配气方法已经广泛应用,但具体的配制精度还没有系统研究。设计并组建了以四级杆质谱仪、质量流量控制器和计算机程控系统为主的气体传感器测试系统,该系统根据质谱仪的测试数据利用线性最小二乘法实时调整质量流量控制器的输出电压,采用LabVIEW8.5编写上位机数据采集软件进行远程闭环控制。对目前工业领域使用量最大的12种危化品气体进行了气体配制,并对配制的部分气体利用Agilent6890气相色谱仪进行了测试分析,给出了该测试系统在常温常压下配制不同浓度混合气体的精度。实验数据表明:该系统配制的气体可以作为工业气体传感器的标定气体使用。

As for the accuracy of dynamic testing system for gas sensors, few systematic researches have been carried on so far. A dynamic high-precision testing system for calibrating gas sensors is reported in this paper. The system is mainly composed of a quad-rupole mass spectrometer, four mass flow controllers and a program controller. This system can produce high accuracy standard gas. Least squares linear fitting is adopted to deal with the spectrometer data and control the data collector in real time. A program developed on LabVIEW8.5 platform is used to control the whole process in a remote location, and to acquire, display and store the signals of 40 channels simultaneously. 12 kinds of hazardous chemical gas sensors most widely used in industry field have been tested and analyzed with this system, and part of these gases were analyzed with Agilent6890. The accuracies of the mixed gases with different concentration are given under the ambient temperature of 20 degrees and pressure of 1atm. The obtained test data show that the mixed gas obtained from this system can be used to calibrate gas sensors in industry field.