A Study on the Effects of Bandwidth of IR Thermometry Measurements

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A Study on the Effects of Bandwidth of IR Thermometry Measurements (342.4 KB)

In the world of low temperature, wide-band infrared (IR) thermometry, there are a number of uncertainties to consider when making measurements. Among these uncertainties are the effects of bandwidth variability for IR thermometers. This uncertainty becomes troublesome because emissivity does not necessarily have a constant value over the entire bandwidth of the IR thermometer being used for the measurement. With this knowledge there is an uncertainty in this measurement that can be determined. Determination of this uncertainty can be rather difficult due to the complexity of the mathematics involved.

This paper addresses this bandwidth related problem when making measurements in the long wave IR or the far IR region, especially the 8-14 μm band. This paper discusses the mathematical problem of calculating this uncertainty. It addresses the numerical theory involved in this calculation. It suggests a method of using simplified mathematics to perform a calculation of this uncertainty. It then discusses practical experimentation performed to verify this method. The reader of this paper will learn how to better calculate this uncertainty for IR thermometry.