Research On The Temperature Measurement Of Infrared Thermal Imaging Based On Dual Band Colorimetric Method

Infrared radiation technology has been one of the high and new technologies at home and abroad.Among them,with the development of infrared detector technology,infrared imaging temperature measurement based on infrared thermography has received more and more attention.In recent years,for the research of infrared imaging precise temperature measurement,many scholars have been committed to the accurate measurement of emissivity,establishing the infrared temperature measurement equation with considering the emissivity factor and improving the data fitting method.In view of the temperature measurement for the objects with different surface emissivity in the same scene,we get the temperature field distribution based on the dual band colorimetric method by using the advanced refrigeration infrared thermal imager,which overcomes the influence of emissivity on the scene and solves the actual problems of the imaging temperature measurement system.To solve the problem of optical parameter selection for the dual band colorimetric method,we draw the curves of central wavelength,wavelength interval and bandwidth of filter in terms of temperature resolution in the range of the required temperature measurement.Taking into account the absorption spectra of the specific molecules in the atmosphere,the appropriate optical parameters are selected and the temperature field image is simulated for the different emissivity objects by using these selected optical parameters.In this paper,an imaging system based on a refrigerating medium infrared thermal imager and two infrared bandpass filters is designed.Aiming at the problem that the system is affected by the spectral responsivity,optical transmission rate and atmospheric attenuation,we use the approximate blackbody surface emitter to correct it.Compared with the traditional method,the corrected dual band colorimetric imaging reduces the uncertainty from 17.5% to 1.4%.