pyro sensor
Pyrosensors are sensors that respond to temperature fluctuations. They are based on the fact that certain ion crystals charge in opposite directions when the temperature fluctuates and generate a voltage.
The crystal lithium tantalate used in pyrosensors has a material-specific pyroelectric constant that is incorporated into the voltage generated. Pyrosensors are used in pyrometers and in passive motion detectors such as the passive infrared motion detector( PIR) and detect the thermal radiation of people and animals.