一种测量发射率的实验装置

An Experimental Apparatus for Emissivity Measurement

基于基尔霍夫定律,研制了一种采用双光路对比法测量中、高温物体发射率的实验装置。该装置由样品加热系统、信号检测与处理系统以及显示系统三部分组成。用该装置测量了两种标准不锈钢样品(光滑钢片和粗糙钢片)在不同温度下的发射率,并采用最小二乘法将测量数据拟合成解析函数。分析了该装置的发射率测量不确定度随温度的变化关系。结果表明,在800 K～1100 K内,光滑钢片发射率的最大不确定度为σ_t=4.26×10^(-3),由此引起的测温不确定度为σ_T=0.497 K,σ_T/T=0.0611%;粗糙钢片发射率的最大不确定度为σ_t=3.80×10^(-3),由此引起的测温不确定度为σ_T=0.415 K,σ_T/T=0.0507%。

Based on the Kirchhoffs law,an experimental apparatus for emissivity measurement at intermediate and high temperatures is developed,in which the double-light-path contrast measurement technique is used.The apparatus consists of three parts：the sample heating system,the signal detection and processing system,and the display system.With this apparatus,the emissivities of two standard samples（polished steel and roughened steel） are measured at different temperatures.The emissivity data of these two samples are fitted to the analytical function with the least-squares method.The measurement uncertainty of this experimental apparatus is analyzed.As a result,over the temperature range from 800 K to 1100 K,the largest emissivity uncertainty of the polished steel isσ_t=4.26×10^（-3）,and the corresponding uncertainty of temperature measurement isσ_T=0.497 K,σ_T/T = 0.0611%;the largest emissivity uncertainty of the roughened steel isσ_t = 3.80×10^（-3）,the corresponding uncertainty of temperature measurement isσ_T=0.415 K,σ_T/T=0.0507%.