利用红外热像仪测量半透明体透射率的方法研究

Measuring Method for Transmittance of Semitransparent Object by Infrared Thermography

针对E1897-97标准未给出半透明体透射率测量的理论模型,也未考虑被测材料温度变化对透射率测量结果影响问题,依据红外测温原理以及E1897-97标准的测量条件和测量方法,推导出了半透明体透射率测量的理论公式;选用了几种不同规格的半透明体双面硅进行了实验测试,将半透明体透射率实验测试值、理论计算值、出厂测量值进行分析比较,得到了在各种温度背景下半透明体的透射率测量值相对于理论计算值的误差,透射率测量值相对于出厂测量值的误差,分析了测量误差发生的原因。提出了一种减少半透明体透射率测量误差的方法,并通过实验进行了验证。实验结果与分析表明:考虑被测材料温度变化,对理论计算公式进行修正,并使用改进的半透明体透射率测量方法,透射率修正值与出厂测量值之间的误差降低到3%以下,证明了改进的透射率计算模型和透射率测量方法的正确性和可行性。

A theoretical model for transmittance measurement of a semitransparent object has not been developed nor has the effects of temperature change of the measured material on transmittance measurement results been considered according to the E1897-97 standard. First, according to the principle of infrared temperature measurement and the measurement methods and conditions under the E1897-97 standard, a theoretical formula for measuring the transmittance of a semitransparent object was derived. Second, several semitransparent double-sided silicon with different specifications were selected, and experimental testing was carried out. Thirdly, the experimental testing values, theory calculation, and calibration values of semitransparent object transmittance were analyzed and compared. The error of the measured transmittance values under different temperature conditions was obtained and compared with theoretical values. The error of the measured transmittance values was also obtained compared with the factory calibration value, and the causes of measurement error were analyzed. Finally, a method to reduce the measurement error of transmittance was proposed and verified by experiments. The experimental results show that by considering the temperature change of the tested material, the theoretical calculation formula was modified, and an improved semitransparent object transmittance measurement method was adopted. The error between the correction value and calibrated value was reduced to less than 3%. Thus, the correctness and feasibility of the improved transmittance calculation model and transmittance measurement method are proven.