曝光一定时单相机辐射测温范围的影响因素分析  

Analysis of the Influencing Factors of Radiation Temperature Measurement Range of a Single Camera at a Certain Exposure

作　　者：黄文丹 马恒 刘战伟[1] HUANG Wendan;MA Heng;LIU Zhanwei(School of Aerospace Engineering,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学宇航学院,北京100081

出　　处：《光子学报》2023年第2期196-208,共13页Acta Photonica Sinica

基　　金：国家自然科学基金(No.11972084)。

摘　　要：针对单相机单波长测温和比色测温过程中测温范围较窄的问题,以单波长测温过程为基础,推导了相机传感器动态范围和工作波长对单相机测温范围影响的理论公式,并对波段选取过程中的影响因素进行了分析。理论分析结果表明:相机动态范围和波长的选取限制了一次曝光时测温范围的最大跨度值,在相机传感器唯一确定时,相机动态范围一定,根据波段选取原则选定工作波段,选定估计温度范围下限之后,由公式即可确定待测温度上限,再根据实际测温范围调整波段和估计测温下限;配合调节曝光及光圈,充分利用相机传感器的全动态范围,可实现单相机辐射测温法中宽温度范围的测量。此外,通过涡流加热实验和熔池温度场测量实验对上述影响因素进行验证,选取更优波长和更优曝光时间,可提高单次测温跨度至少40%,为单相机测温技术的具体实施提供技术参考。As a common means of non-contact temperature measurement technology,radiation temperature measurement is often limited by the performance of the detector,and the temperature measurement range is narrow,which can not meet the measurement needs of wide temperature range distribution.The analysis of radiation temperature measuring range and influencing factors of a single camera has certain application value in practical engineering applications.As the error of temperature measurement is an important issue to be considered in the process of temperature measurement,this paper briefly introduces the principle of monochrome temperature measurement and two-color temperature measurement and analyzes the influence mechanism of temperature measurement error in detail.The accurate measurement of emissivity is the key factor affecting the error of temperature measurement in the monochromatic method.The accuracy of the colorimetric method is higher than that of the monochromatic method,which can meet the need of temperature measurement accuracy in actual working conditions.Aiming at the problem that the temperature range of the single camera is narrow in the process of single wavelength temperature measurement,the process of object radiation energy conversion into camera and imaging is introduced in detail from the process of single wavelength temperature measurement,and the theoretical formula of the influence of camera sensor dynamic range and working wavelength on the temperature range of the single camera is derived.Combined with the formula,then the influence mechanism of exposure time on the temperature range of radiation thermometry was analyzed,and the influencing factors in the process of band selection are analyzed.The reference principle of band selection is given to select the band where the object radiation is stronger than diffuse reflection and ambient light as far as possible.In colorimetric thermometry,the selection of two working bands should be close to meet the premise that the emissivity of the two bands

关 键 词：光学测量 宽测温范围 辐射测温 相机成像 动态范围 比色测温技术 

分 类 号：TK311[动力工程及工程热物理—热能工程]