发热筛查热成像系统的测温准确性分析

Analysis of Temperature Measurement Accuracy in Fever-Screening Thermograph

介绍了发热筛查热成像系统的发展历程和系统构成及热像仪测温的基本原理,指出热像仪的内辐射对测温准确性具有明显影响,分析了发热筛查热成像系统用黑体参考源消除内辐射影响的工作原理。介绍了发热筛查热成像系统的测温准确性评价模型及其主要参数的要求,逐项分析了这些参数与热像仪噪声、黑体参考源及使用环境等因素的关系,发现热像仪的时间低频噪声和空间低频噪声是影响测温准确性的关键因素,指出黑体参考源可以消除时间低频噪声的影响,基于外挡片的两点校正法可以消除空间低频噪声的影响,从而使发热筛查热成像系统满足人体测温准确性要求。

The development and system composition of a fever-screening thermograph and the basic principle of a thermal imager’s temperature measurement are introduced.It is observed that the thermal imager’s internal radiation clearly influences the accuracy of the temperature measurement.This paper introduces an evaluation model for the temperature measurement accuracy of a fever-screening thermograph and its main parameters.By analyzing the relationship between these parameters and the thermal imager noise,the blackbody reference source,and the environment,the temporal and spatial low-frequency noise of the thermal imager are found to be the key factors affecting the accuracy of the temperature measurement.Moreover,the influence of temporal low-frequency noise can be eliminated using a blackbody reference source,and the influence of spatial low-frequency noise can be eliminated using the two-point correction method based on an external shutter.Thus,the fever-screening thermograph can meet the accuracy requirements of human body temperature measurement.