New Thermal Imaging System Applying Two-color Thermometry

这项研究涉及一种使用热像仪的新型热成像系统。该成像系统使我们能够可视化具有未知发射率的物体的温度。将双色测温应用于传统的温度成像是通过使用相应的带通滤光片将热成像的可检测波长范围划分为两个不同的范围来执行的，即当从感兴趣的物体发射的辐射能量一次通过一个滤光片时，得到与每个滤光片的波长范围相对应的能量分布。如果预先知道每个物体的两个波长范围的发射率之间的关系，则可以从这两个能量分布构造热像。这里，我们假设任何物体的两个发射率相等，这是合理的，因为可以检测的波长范围很窄，并且每个发射率的波长彼此接近。我们证明了改进传统热像仪的系统是…更多的问题是，我们需要拍摄具有不同温度和未知发射率的物体的正确热像。并进行了误差分析，提高了温度成像的精度。假定成像器的可探测波长范围在同一波长被分成两个范围，即较短的波长范围和较长的距离，数值研究了波长范围对成像温度误差的影响。在数值分析中，温度传感器的单色特性等几个参数是由具有可检测波长范围3.0-5.4um的InSb传感器的商用温度传感器给出的。分析表明，该系统存在使成像温度误差最小的最佳值，并与常规热成像系统的成像温度精度进行了数值比较。如果在常规系统中能够准确地给出感兴趣目标的发射率数据，则本系统的成像温度误差大约是常规系统的十倍。较少

This study deals with a new thermal imaging system using a thermography. The imaging system enables us to visualize temperature of objects with unknown emissivities.Applying two-color thermometry to conventional thermography is performed by dividing the detectable wavelength range of thermography into two different ranges using respective band-pass filters, i.e., when the radiation energy emitted from objects of interest is passed through one filter at a time, the energy distribution corresponding to each filter's wavelength range is obtained. A thermal image can then be constructed from the two energy distributions if the relation between the emissivities of the two wavelength ranges for each object is known in advance. Here, we assume the two emissivities of any object are equal to each other, which is reasonable since the detectable wavelength range is narrow and the wavelengths in each are close to each other.We demonstrated that the system modifying a conventional thermography ena … More bles us to take a correct thermal image of objects having different temperatures and unknown emissivities. Furthermore, error analysis has been carried out to improve the accuracy of imaged temperature. Assuming that the imager's range of detectable wavelength is divided into two ranges at a wavelength, lambdad ; the shorter range than lambdad and the longer range, the effect of lambdad on the error of imaged temperature has been numerically investigated. In the numerical analysis, the several parameters, such as the monochromatic characteristics of the thermograph's sensor, are given by those of a commercial thermograph having an InSb sensor with detectable wavelength range of 3.0 - 5.4 mum. This analysis revealed that there is the optimum value of lambdad which minimizes the error of the imaged temperature.The accuracy for imaged temperature in this system has been numerically compared with that of a conventional thermal imaging system. The error of imaged temperature in the present system is about ten times larger than that in conventional system, if the emissivity data of objects of interest can be precisely given in the conventional system. Less