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Passive infrared sensors detect the infrared radiations from outer source.When an object is in a field of view of a sensor it provides a reading based on a thermal input.It dose not generate any infrared.There are different kind of Passive infrared sensor.
- Thermal passive infrared sensor
- Thermocouple thermopie and Bolometer
- Pyroelectric infrared senor
Pyroelectric infrared sensor(PIR)
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