辐射温度计的等效波长及其应用

Equivalent wavelength of radiation thermometer and its applications

经典的有效波长和亮度温度理论仅适用于高温测量等可忽略环境辐射影响的场合。考虑了环境辐射影响,基于中值定理推导并定义等效波长,用于简化测温数学模型。用有效辐射和等效波长概念定义单色和带通辐射温度计的测量结果——亮度温度。阐述了等效波长的计算方法。利用矩形带通光谱响应近似模型,解决了难以测定光谱响应度的宽带辐射温度计的等效波长计算问题。针对(8～14)μm宽带辐射温度计计算了等效波长,可简化计算和不确定度评定。在应用实例中分析了黑体辐射源发射率对宽带辐射温度计校准的影响和用黑体辐射源直接校准发射率设定值为0.95的宽带辐射温度计的方法误差。

Classical effective wavelength and radiance temperature theories are restricted to the cases in which the ambient radiation influence can be neglected, especially to high temperature measurement. The equivalent wavelength is deduced and defined by considing the influence of ambient radiation, and adopted to simplify the mathematical model of temperature measurement. The effective radiation and equivalent wavelength concepts are used to explain the measurement results of monochromatic and bandpass radiation thermometers-the radiance temperatures. The calculation method for the equivalent wavelength is deeribed. The simplified rectangular bandpass model for spectral responsivity is proposed to make equivalent wavelength calculation feasible for the board band radiation thermometer （BBRT）, whose spectral responsivity is difficult to measure. The calculation results of the equivalent wavelength are given for （8 -14） μm BBRTs to simplify the mathematical calculation and uncertainty estimation. The influence of the non-ideal blackbody radiator emissivity on the calibration for BBRT and the calibration error of the method using blackbody radiators for the BBRT with 0.95 emissivity setting are analyzed as examples.