Blackbody calibrators are often used at the reference level of radiation thermometry because of their higher emissivity value. Other types of infrared temperature calibrators, known as flat-plate IR temperature calibrators, have a painted target surface that is heated or cooled to the required calibration temperatures.

A blackbody calibration source is a tool for checking the calibration of an infrared temperature sensor. It consists of a heated (or cooled) target object whose temperature is precisely known and is the basis for the accurate calibration of infrared pyrometers.

The thermal radiation source is a calibrated temperature source that provides radiation. The strength of the radiation is dependent on the source's temperature; this radiation is what the infrared thermometer uses to determine temperature.