Research and application of MQ-7 sensor compensation method

The issue of AQI is a hot topic of public concern today and monitoring the main pollutants in the air is a prerequisite for addressing AQI issues. Research has shown that CO plays a major role in AQI and accurate monitoring of CO concentration in the air is particularly important. CO monitoring generally uses MQ-7 sensors, which needs to solve the problems of sensitive body resistance heating and temperature and humidity compensation during use. In response to these problems, a hardware compensation circuit with dual power supply cycle rotation heating is designed in this paper. At the same time, temperature and humidity data in the tested environment is obtained through the sensor. Based on the temperature and humidity characteristics of MQ-7, software compensation is used to improve its monitoring accuracy. Finally the article verifies through experiments that this method can make MQ-7 not affected by temperature and humidity, and accurately monitor the CO content in the air.