General Purpose and Omni-directional Quad Element Pyroelectric Infrared Radial SensorThe pyroelectric infrared sensor detects infrared radiation on the basis of thecharacteristics that the self-polarization of pyroelectric material changes withtemperature. Quad sensing elements are applied to suppress the interference resultingfrom circumstance temperature variation， to raise signal output and to be sensitive inall directions. This type senor has the technical merits of both single and dual type.Asa result， the operating stability of the sensor is greatly improved. It can be widely usedin many applications such as in automatic light switch control，security systems，burglar alarms， visitor acknowledgement and intellectualized toy， etc.，especially in thefield of ceiling mount applications.

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