CO₂ Sensor Performance Test Based On Controllable Temperature And Pressure Calibration System

At present,China's rapid urbanization process has brought greater pressure on the urban agglomeration resources and environment.High-carbon urban construction model has become a bottleneck restricting China's sustainable development.In order to provide continuous,reliable and accurate atmospheric environmental elements and carbon dioxide concentration detection criteria on the urban scale,a comprehensive understanding of the spatial patterns of carbon dioxide in different urban spaces and at different scales is required,and a large number of carbon dioxide detectors need to be placed in the urban areas to monitor different environments.The actual CO₂ concentration,so test the performance of the CO₂ sensor.In this paper,20 K30 CO₂ sensors are used as evaluation objects.According to the Lambert-Beer law,a NDIR?Non-Spectral Infrared?sensor measurement model is established to obtain the relationship between gas concentration and temperature pressure;a low-cost K30sensor is designed.Collecting temperature,pressure and humidity integrated CO₂ module;establishing a temperature and pressure control system of carbon dioxide sensor calibration,can set different temperature and pressure points in the vacuum closed,self-circulation environment,the K30 CO₂ module Performance test,collecting K30 readings under different temperature and pressure combinations.Using the Picarro analyzer as a standard device,20K30 readings were evaluated and corrected through data analysis.After the performance test of the K30 sensor,in the control pressure thermostat test and temperature control and pressure regulation test,after correcting the K30 raw reading with the pressure correction formula and correction value,the deviations of other K30 and Picarro monitoring values except for some sensors About 5ppm;in the initial pressure of 0.7atm,0.8atm and 0.9atm temperature balance test,the relative deviation of K30 and Picarro is reduced to about 50ppm by correction;in the continuous temperature rising and cooling balance test with an initial pressure of 0.9atm,The correction reduces the hysteresis error of K30 and reduces the relative deviation to about 20ppm.