PIR Motion Sensors
These sensors utilise the detection of infrared that is radiated from all objects that emit heat. This type of emission is not visible to the human eye, but sensors that operate using infrared wavelengths can detect such activity. They are sometimes referred to as ‘motion detectors’, as they sense the presence of people, animals and objects through the movement of their infrared wavelengths.
When the sensor detects motion, it opens a relay, breaking the circuit and triggering the alarm.
