本文针对当前红外成像系统性能测试中存在的问题, 设计了一种用于检定红外热像仪最小可分辨温差的表观温差发生器。基于该温差发生器的结构模型, 对温差发生器单元的表面发射率进行计算, 分析了材料发射率、槽的深宽比、槽翅宽度比对单元的表面发射率的影响。通过理论计算, 分析得出槽的深宽比是影响单元表面发射率最主要的因素。使用红外测温仪分别测量了不同温度下不同槽深宽比的单元表观温度。实验结果表明, 这种温差发生器能够通过调整加热温度形成可调节的表观温差。

In view of the problems existing in the performance test of infrared imaging systems, an apparent temperature difference generator was designed to detect the minimum distinguishable temperature difference of a thermograph. Based on the structure model of the temperature difference generator, the surface emissivity of the temperature difference generator unit was calculated and the influence of the material emissivity, the depth-to-width ratio of the groove, and width ratio of groove fin on the surface emissivity of the unit were analyzed. Through theoretical calculation, it was observed that the depth-to-width ratio of the groove is the most important factor affecting the surface emissivity of the cell. The cell apparent temperature were measured at different temperatures and different depth-to-width ratios of the groove, using an infrared thermometer. The experimental results demonstrated that the thermoelectric generator can adjust the apparent temperature difference by adjusting the heating temperature.