(Passive InfraRed sensor) A device used to detect motion by receiving infrared radiation. When a person walks past the sensor, it detects a rapid change of infrared energy and sends a signal. PIR ...
A year ago [Lochie] bought an Airwick automatic air freshener, and while he thought it was a cool gadget, the freshening spray and the novelty ran out in short order. The device collected dust in his ...