IR thermometers capture the invisible infrared energy naturally emitted from all objects. Infrared radiation is part of the electromagnetic spectrum, which includes radio waves, microwaves, visible light, ultraviolet, gamma, and X-rays. Infrared wavelengths are usually expressed in microns with the infrared spectrum extending from 0.7 microns to 1000 microns. There are several important factors that determine accurate measurement; emissivity, distance to spot ratio, field of view and location of a hot spot. There are many advantages to using a non-contact temperature measurement tool such as the infrared type shown. They are fast, allowing for more measurements and accumulation of data, they allow for measurement of moving targets, as well as hazardous or physically inaccessible objects, there is no risk of contamination and no mechanical effect on the surface of the object, soft surfaces can be measured, and energy from the target is not lost or consumed to make the measurement. Measurements are extremely accurate as there is no distortion on poor heat conductors as compared to measurements with contact thermometers that act as heat sinks.