Bower S M, Kou J, Saylor J R
Department of Mechanical Engineering, Clemson University, Clemson, South Carolina 29634-0921, USA.
Rev Sci Instrum. 2009 Sep;80(9):095107. doi: 10.1063/1.3213075.
Presented here is an effective low-cost method for the temperature calibration of infrared cameras, for applications in the 0-100 degrees C range. The calibration of image gray level intensity to temperature is achieved by imaging an upwelling flow of water, the temperature of which is measured with a thermistor probe. The upwelling flow is created by a diffuser located below the water surface of a constant temperature water bath. The thermistor probe is kept immediately below the surface, and the distance from the diffuser outlet to the surface is adjusted so that the deformation of the water surface on account of the flow is small, yet the difference between the surface temperature seen by the camera and the bulk temperature measured by the thermistor is also small. The benefit of this method compared to typical calibration procedures is that, without sacrificing the quality of the calibration, relatively expensive commercial blackbodies are replaced by water as the radiative source (epsilon approximately 0.98 for the wavelengths considered here). A heat transfer analysis is provided, which improves the accuracy of the calibration method and also provides the user with guidance to further increases in accuracy of the method.
本文介绍了一种有效的低成本方法，用于0至100摄氏度范围内应用的红外热像仪温度校准。通过对上升水流进行成像，实现图像灰度强度到温度的校准，水流温度用热敏电阻探头测量。上升水流由位于恒温水槽水面下方的扩散器产生。热敏电阻探头保持在水面正下方，并调整从扩散器出口到水面的距离，使得水流引起的水面变形较小，同时相机看到的表面温度与热敏电阻测量的水体温度之间的差异也较小。与典型校准程序相比，该方法的优点是，在不牺牲校准质量的情况下，相对昂贵的商用黑体被水替代作为辐射源（对于此处考虑的波长，发射率约为0.98）。提供了传热分析，这提高了校准方法的准确性，并为用户进一步提高该方法的准确性提供了指导。
