Error analysis and accurate temperature measurement method of infrared thermal imaging long-distance temperature measurement in underground mine

In order to monitor the high-temperature heat sources underground in coal mines in real time.detect mine fires and give an alarm.this paper analyzed the error of long-distance temperature measurement of mine infrared thermal imaging.and proposed a long-distance accurate temperature measurement of mine infrared thermal imaging.which has passed the test verification. First.the functional relationship between the single-wave radiation illuminance received by thermal imager and the image gray level is established.and the radiation temperature measurement formula of the thermal imager is obtained. Secondly.through the analysis of the concentration and absorption intensity of the main components in the mine air.the environmental parameters that affect the accuracy of long-distance temperature measurement of mine infrared thermal imaging are confirmed. In addition.the influences of water vapor.CO2.CH4 and SO2 absorption and dust scattering in the radiation path on the accuracy of infrared temperature measurement are analyzed. Thirdly.the mine air permeability is corrected in real time in combination with the on-site environmental conditions. According to the absorption attenuation of water vapor.CO2.CH4 and SO2.and the scattering attenuation of dust.the attenuation model of the total mine air permeability and the radiation temperature measurement distance was constructed. Finally.combining the radiation temperature measurement formula of the thermal imager.the functional relationship between the single-wave radiation illuminance and the image gray level.and the attenuation model of mine gas and dust.a long-distance accurate temperature measurement method for infrared thermal imaging is proposed and verified by experiments. The experimental results show that the temperature of the object measured by the proposed method is closer to the true temperature of the object. The temperature change of the target surface has little effect on the temperature measurement accuracy.but the radiation attenuation in the temperature measurement path has a greater impact on the temperature measurement accuracy. As the temperature measurement distance increases.the total transmittance of infrared radiation gradually decreases. At a temperature measurement of 35 m.the average relative error measured by the thermal imager's own algorithm is 12.22%.the average relative error measured by the precise temperature measurement method is 2.85%.and the temperature measurement error is greatly reduced.