目标距离与角度对红外热成像仪测温精度影响分析

Influences of Target Distance and Angle on Temperature Measurement Accuracy of Infrared Thermal Imager

红外热成像仪是一种非接触、高效率、高精度测温设备.在当前新型冠状病毒流行时期,红外热成像测温技术快速发展,为及时防控、筛查、隔离高温疑似人群做出了突出贡献.红外热成像测温技术是标定测温,测温精度除了受到被测物体辐射温度、环境反射温度、大气温度和探测器温度等因素影响外,目标距离红外热像仪的远近也对测温精度有影响.目前已有大量研究人员针对目标与热成像仪之间的距离对测温结果的影响进行了研究,但影响模式缺乏理论基础分析,影响形式及结果仍然存在分歧.通过对红外测温原理进行研究,理论公式推导,建立模型,分析了点源目标与面源目标在测温过程中与热成像仪之间的距离和角度对测温结果的影响.提出了在设计过程中,应该注意的因素及探测器、光学镜头等设计指标选取.同时进一步研究了人体测温过程中距离变化对测温结果的影响,提出了提升测量准确度的补偿方法.经过研制实验装置,对测温数据进行了拟合与补偿,补偿后对测温精度进行了评价,测温标准方差在0.14℃以内,达到了理想的效果,提升了测温精度及测温一致性.

An infrared thermal imager is a type of noncontact,high-efficiency,and high-precision temperature measuring equipment.Because of the recent 2019-nCoV,infrared thermal imaging temperature measurement technology has rapidly developed,and it has made outstanding contributions to the timely prevention,control,screening,and isolation of people displaying symptoms such as high temperature.Infrared thermal imaging temperature measurement technology is based on a calibration temperature measurement system,and its temperature measurement accuracy is affected by the radiation temperature of the measured object,ambient reflection temperature,atmospheric temperature,detector temperature,and distance between the target and the infrared thermal imager.A large number of researchers have studied the influence of the distance between the target and the thermal imager on the temperature measurement results.However,the influence mode lacks theoretical basis analysis,and there are differences in the influence forms and results.By studying the principle behind infrared temperature measurement,deducing the theoretical formula,and establishing a measurement model,the influence of the distance and angle between the point source target or nonpoint source target and the thermal imager on the temperature measurement results is analyzed.Important factors in the design process and selection of design indexes such as detector and optical lens are mentioned.After developing the experimental device,the temperature measurement data were fitted and compensated,and the temperature measurement accuracy was evaluated after compensation.By measuring human body temperature,with the device,for various distances,the influence of distance on the temperature measurement results was studied,and a compensation method to improve the measurement accuracy is suggested.The temperature measurement results show a standard deviation of 0.14℃.The results achieved the ideal effect,and the device improved the temperature measurement accuracy and consistency.