非制冷热像仪内部温升对测温精度的影响修正

Correction of temperature measurement accuracy affected by internal temperature rise in uncooled thermal imager

随着非制冷型热像仪工作时间的增长,其内部器件、机械结构所积累的热量越来越多,其温升所导致的热辐射势必会对热像仪的测温精度产生严重影响。因此,要实现热像仪的准确测温,必须对其内部的各温升影响因素进行相应的修正。本文通过对影响测温精度的镜筒辐射温度、探测器靶面温度以及热像仪工作累积时间三个因素进行评估和建模,并对其相互关系进行评价,根据数据模型对热像仪辐射测温值进行修正。结果表明,在实验室条件下,经过修正,非制冷型红外热像仪测温精度可控制在±1℃以内,其稳定性可控制在±0.5℃以内。修正后的温度结果基本不受内部温升的影响,有效的提高了非制冷测温型热像仪的稳定性、可重复性以及测温精度。

With the increase of the operating time of uncooled infrared thermal imager,the internal devices and mechanical structures accumulate more and more heat,and the thermal radiation caused by the temperature rise is bound to have serious effects on the accuracy of the thermal imager. Therefore,in order to achieve accurate temperature measurement of the thermal imager,it is necessary to correct the internal temperature influencing factors. This paper evaluates and models the three factors that affect the accuracy of temperature measurement： the barrel radiation temperature,the temperature of the target surface of the detector,and the cumulative working time of the thermal imager,and evaluates the relationship among them. Finally,the temperature measurement of the thermal imager is corrected according to the data model. The results show that un-der the laboratory conditions,the temperature accuracy of the uncooled infrared camera can be controlled within ± 1 ℃,and its stability can be controlled within ± 0. 5 ℃. The corrected temperature is basically independent of the internal temperature rise,thus effectively improves the stability,repeatability,and accuracy of the temperature measurement of the uncooled thermal imager.