Gas Sensor Based On Virtual Instrument Automated Test System

This thesis examines the characteristics and problems of the present gas sensors test system, points out the inevitable appearance of Virtual Instrument, and explains the concept of VI, its hardware and software structure, its characters and applications. It also compares the difference of the three most popular projects, and develops a system based on the programmable Data Acquisition (DAQ) system-KEITHLEY2700 and the DAQ card and the graphic programming language-LabVIEW. The principle of this system is: Use the DAQ card to control system-cleaning and gas-mixing, use the programmable power to control sensors-heating, use the DAQ system-KEITHLEY2700 to acquire the gas sensors' dynamic signals, then the data is dealt with by the software of system.In the following chapters, the test system is illustrated at length, including the design of hardware and software structure, mainly the makeup of hardware, and the development of Lab VIEW software.The functions of virtual gas sensors test system are listed in detail. Finally, this thesis analyses and compares the data acquired by this test system. The conclusion then can be safely drawn that this system is proved to be successful, while the prospect and the cause of error of this system are provided at the same time.