Calibration Body

A calibration radiator emits thermal radiation at a known temperature within the range detected by an infrared thermometer. This temperature is traceable to the International Temperature Scale, and different temperatures can be set for calibration. The goal is to compare the target values with the measured values.

While an ideal thermal radiator is a black body, such perfection doesn’t exist in reality. It’s challenging to achieve low reflectivity over a wide wavelength range, along with temperature resistance and cost-effectiveness. This has made it difficult to create a blackbody radiator using specific coatings. The best technical approximation of a black body is a calibration radiator, which would typically be a hollow, uniformly heated cylinder with a high emissivity surface and a length-to-diameter ratio of around 5. Such cavity radiators have an effective emissivity of about 0.99 over a wide spectral range. In contrast, the emissivity and radiation temperature of a panel radiator depends on the sensitive spectral range of the infrared thermometer used.