Q. What is the ideal target area for measurement via infrared thermometer?

Answer

The ideal target area is area that is at least twice the size of the spot at that distance. When we have smaller areas relative to distance it would result in less accurate measurement. An infrared thermometer therefore is supposed to be placed too close to its target since the close distance could cause heat to build up in the thermometer's housing and damage the sensor. Measurement through infrared thermometer only decreases with too much distance.