Automated Test System For Gas Sensors

An automated test system for semiconductor gas sensors is constructed in this thesis. The system is composed of a computer, a programmable DC power supply Agilent 6626A, a 82350A GPIB card, a data collect card PC-6342, a D/A card PCI-6208V, 4 mass flow controllers made by UNIT, 2 DC power supply made in TaiWan, test gas, test chamber and semiconductor gas sensors test circuit.A programmable DC power supply with four output channels is used to heat up-gas sensors through GPIB card in the system. A computer is used to control MFCs to accurately offer testing gases in low concentrations, and to collect the responses of gas sensors by data collecting card in real time; At the same time 8 different color data curves corresponding to different data channels of the A/D card are displayed in the surface of the test system, and the voltage signal data of gas sensors to tested gas is saved in text file to be processed. In addition, in order to satisfy user' s requirement of processing data , the data text file can be changed into the EXCEL file in which the data processing and data plotting ability are sufficiently used.In soft design of the system, the multimedia timer of Visual C++6. 0 is used to control data collect interval and the tested gas flow time in the test chamber to dynamically test the gas sensors response signal under different conditions.All kinds of operating function of the test system > friendly user operating surface and convenient data analysis provide reliable data for the research of semiconductor gas sensors.