Development of high-precision gas sensor test system

1 Introduction Gas sensors have a wide range of applications in industry and daily life, especially combustible gas sensors play a pivotal role in fire and explosion protection. This type of sensor is mainly used to measure flammable gases in the environment such as hydrogen, natural gas, and gas. It is usually made into an alarm to monitor the concentration of combustible gas in the air. When the concentration exceeds the index 1 Introduction Gas sensors have a wide range of applications in industry and daily life, especially combustible gas sensors in fire and explosion protection. Play a pivotal role. This type of sensor is mainly used to determine the concentration of flammable gases in the environment such as hydrogen, natural gas, gas, etc., and is usually made into an alarm to monitor the concentration of combustible gas in the air. When the concentration exceeds the index, The sensor will output a warning signal to trigger the alarm device. The accuracy of the sensor parameter calibration is very important, because once the calibrated parameter has a deviation, the sensor will falsely alarm at a non-specified concentration, and it is not advisable to alarm too early or too late. In order to calibrate the parameters of the gas sensor accurately and quickly, we use the 80c196 single-chip microcomputer combined with the logic circuit to develop a multi-channel gas sensor parameter test system with high test accuracy, fast speed, and communication with the computer. 2 hardware circuit design The hardware circuit of the multi-channel gas sensor parameter tester is shown in Figure 1. The A/D converter that comes with 80c196 is used to accurately measure the standardized parameter voltage. Due to the large number of sensors to be measured at one time, a channel switching control circuit is designed to facilitate time-sharing measurement. In order to improve the safety of testers, the tester communicates with the computer remotely through the serial port, which can conveniently use the computer to remotely operate the sensor test and save and print the measurement results.