There are a few instruments used to perform infrared (IR) thermometer and IR imager calibration. These instruments fall into two categories, cavities and flat-plates. To calculate the uncertainty in using these instruments, the temperature uniformity must be known. This is especially true with flat-plates. This uncertainty may be given in an instrument’s specification. However, there is not a standardized test method to test the uniformity of a flat-plate calibrator as there is with other classes...