Low-cost Indoor Air Quality Sensor Calibration Technology And Performance Optimization Method

At present,the problem of environmental pollution has become an issue that cannot be ignored.More than 70%of people spend their time indoors,so indoor environmental issues are more important.At present,the main pollutants in the indoor environment are PM_2.5,CO₂,formaldehyde,VOC,etc.The prerequisite for removing these pollutants is to accurately obtain their content in the air.As a result,more and more indoor pollutant detection technologies are beginning to emerge.This paper starts with the common pollutant monitoring methods in indoor air,investigates the current common pollutant monitoring methods,and compares their advantages and disadvantages.A method of constructing a sensor array using a low-cost IAQ sensor is proposed to conduct long-term monitoring of residential IAQ.At the same time,a 1m³ low-cost IAQ sensor calibration chamber was built,and the method of calibrating the low-cost PM_2.5 sensor and CO₂ sensor was studied.Using the platform,the low-cost PM_2.5 sensor commonly used in the market was investigated.It was found that most of the sensor errors are far from the manufacturer’s trademark of±10%,and even 100%at high PM_2.5 concentration.Indication error.At the same time,a 3m³closed environment chamber was built,and the influence degree of different relative humidity on the measurement results of the light scattering PM_2.5 sensor was studied.The results show that the variation of the measurement results of the sensor in different dust source environments is different;when the relative humidity of the environment is less than50%,the influence on the measurement results of the sensor is negligible,and when the relative humidity is greater than 50%,the measurement of the sensor is required.The results were corrected and a preliminary correction formula was proposed.