Infrared Thermometers are devices for measuring the temperature. The difference between these temperatures with other temperatures is that they can determine the temperature of surface of objects without needing to touch them. Infrared thermometers can measure the temperature of objects without making direct contact. This is because they measure the energy being radiated from an object. Objects that their temperature is above zero emit infrared energy. The hotter an object, the more infrared energy it emits. Main components of an infrared thermometer consist of a processing unit , an optical system and detector. The process goes like this: Objects emit infrared energy , the optical system gathers this energy and then pass it through to the detector. The detector transforms the infrared energy into electrical signals. Finally these signals change in the processing unit into a temperature measurement.