Research On The Expansion Method Of Wide Dynamic Ultra-high Temperature Radiation Of Mid-infrared Camera

Explosive ultra-high-temperature flame infrared radiation temperature measurement is one of the important means to obtain the infrared radiation characteristics of the target under test at the target range,as well as to study the explosion mechanism and thermal damage assessment based on.With the rapid development of new munitions,the demand for ultra-high temperature(above 3000°C)measurements is increasing.Short-wave infrared is more advantageous in ultra-high temperature measurement,but due to the short-wave infrared lens is expensive,frame rate is low and can not fully record the explosion dynamic flame more details;and medium-wave infrared camera frame rate is high,but by the infrared wavelength limit by the Wien’s law can not be ultra-high temperature measurement.Therefore,based on the theory of infrared radiation,this paper focuses on the physical model of mid-wave infrared multi-range segment temperature measurement and extends the derivation of a simplified calibration model for any range segment radiation to realize mid-wave infrared wide dynamic ultra-high temperature measurement.The specific work is as follows:First,based on the principle of infrared radiometric temperature measurement and calibration,a mid-wave infrared calibration model with the introduction of integration time combined with neutral attenuation sheet is derived and blackbody simulation tests are conducted.Analyze the error caused by the introduction of the attenuation sheet and derive the method of attenuation sheet transmittance correction and elimination of its own radiation to improve the accuracy of expanding the wide dynamic ultra-high temperature range.Second,by analyzing the radiation calibration model and formula derivation under different conditions of mid-wave infrared thermal imaging camera,Presented a simplified radiation calibration model for mid-wave infrared multi-range,and verify the model inversion temperature by blackbody calibration,the maximum error is 7.7% and 5.8% in the two narrow range segments of the expansion,which not only improves the calibration efficiency but also has good accuracy.Third,the actual explosion test data verification.In order to finally expand the realization of the target field wide dynamic ultra-high temperature measurement,first against the colorimetric thermometer for black body calibration,measured radiation responsiveness,system bias and the digital output value of each wavelength.Then,based on the colorimetric thermometer temperature measurement principle,we simplify and derive the colorimetric“high temperature segment break point”correction method,and make calibration corrections to the colorimetric thermometer high temperature segment to provide standard values for the expansion of the mid-wave infrared inversion ultra-high temperature segment test.Secondly,according to the derived simplified calibration model,inversed mid-wave infrared in the1200～2500°C range band ultra-high temperature expansion range.Finally,three groups were conducted: 5kg-TNT,10kg-TNT,and 10kg-TNT range explosion test tests,to compare the ultra-high temperature segment of the extended inversion with the temperature standard value,and to obtain the change of the mid-wave IR from 11.2%～6.5% to 7.4%～3.6% of the error range before the extension,which further expands the application of mid-wave IR in the field of wide dynamic ultra-high temperature measurement.