Thermal Infrared Detectors, one type of IR Sensor, are distinguished by the advantages of a wide wavelength response, no requirement for cooling, high-temperature stability, high signal-to-noise ratio and low cost. Consequently, they are widely used in consumer products and in instrumentation. In a Thermal Detector, the incident radiation is absorbed to change the temperature of the material, and the resultant change in some physical properties is used to generate an electrical output. Thermal Sensors are differentiated between Pyroelectric and Thermopiles.