Second Calibration of Atmospheric Transmission Coefficient on Accurate Temperature Measurement of the Infrared Thermal Imager in Field

This paper treats the second calibration of atmospheric transmission coefficient with a view to achieving the accurate temperature measurement in field by the infrared thermal imager. A calibrating model for temperature measurement by the infrared thermal imager with a far distance in field is built and a standard expanded area blackbody and an infrared thermal imager for temperature measurement are employed to make the second calibration of atmospheric transmission coefficient. At first, the set temperature of the standard expanded area blackbody is used to determine the second atmospheric transmission coefficient. Then, given the known emissivity of the interested area of the target object, the infrared thermal imager calibrates the measured temperature of the unknown radiation object with the second atmospheric transmission coefficient. With this method, the accurate measurement of the radiation temperature of the unknown radiation object is achieved, and in turn, the accurate temperature measurement in field by the infrared thermal imager is ensured.