Black body calibration sources by Nagman are used to calibrate infrared temperature devices that are used to measure temperature. Infrared devices can measure extreme temperatures that are very high as well as very low. They allow to measure temperature from a safe distance from the device that is heated or cooled. Calibrating the infrared temperature devices at regular intervals is very important to ensure an accurate and error free measurement. Black body calibration sources allow for an accurate calibration of the temperature devices.