目标距离和视场角变化对红外热像仪测温精度影响的理论分析

Analysis of Effections on the Precision of Temperature Measurement Using Infrared Thermal Imaging System with the Change of Object Distance and Field

红外热像仪进行测温时,目标距离和视场角变化,会大大降低测温精度。根据几何光学和红外目标辐射理论,推导出温度测量误差与目标距离和视场角之间的关系式,并结合研制的一套红外热像仪系统参数,计算了温度测量误差。提出了提高测温精度的方法,采用此方法,对相同条件下的物体测温,测量误差仅为-0.22℃,在很大程度上减小了目标距离和视场角变化对红外热像仪测温精度的影响。

The change of object distance and field would enormously decrease the precision of temperature measurement using infrared thermal imaging system.In the paper,on the basis of theories of geometry optics and infrared object radiation,formulas of tolerance of temperature measurement relations with object distance and field were given.Tolerance of temperature measurement was calculated using the parameters of a designed infrared thermal imaging system.If temperature compensation would not be done,tolerance of temperature measurement would get to-3℃ which is too big to satisfy the precision of temperature measurement,when the temperature of the object is 300K,the distance is 3m,and the field is 4？ Basing on the analysis,a method of improving the precision of temperature measurement was given,the tolerance would be just-0.22℃ to the same situation if the method was taken,which could reduce the effect on the precision of temperature measurement using infrared thermal imaging system with the change of object distance and field.