Every object whose temperature is above absolute zero emits Radiation. The infrared Sensor captures the emitted Radiation and deflects this to one or more detectors. The energy of the infrared Radiation is converted into electrical signals in the detector, which are then converted into temperature values based on the calibration of the Sensor and the specified Emissivity. All bodies emit infrared Radiation in three different ways. They can emit Radiation, reflect it from the surroundings or transmit it through itself. How the individual factors interact depends on the material of the Measurement object. However, only the emitted Radiation is important for measurements.