I have a new light that has a 'PIR' sensor - what does that mean?
A PIR sensor is a type of motion sensor.
PIR stands for "Passive Infrared", and means that the sensor detects movement by heat changes, in other words if something with heat (like a human body) moves in front of the sensor, the heat differential will set it off.
PIR is passive infrared.
Infrared is the band of electromagnetic energy which we feel as heat.
Passive is because the sensor just sits there, it does not emit energy.
PIR is a sensor that uses heat.
Most PIR sensors work between 5m and 12m, depending how sensitive they are.
The great think about PIR sensor is that they are only sensitive to heat, so for example branches or leaves flying past will not set it off.
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