PIR Motion Sensors
How Passive Infrared Sensors Work
Passive infrared (PIR) sensors use two slots to detect changes to the heat pattern of a room. When the room is unoccupied, both halves of the sensor detect the same ambient temperature of the room and the lights remain off. Once a person enters the room, the nearest sensor detects a higher heat signature than the other half. This creates a "positive differential" charge between the two slots and the motion sensor turns the lights on. PIR sensors are calibrated to only turn the lights on at a certain change threshold to keep the lights from turning on for small animals or the heat from a window, but false trips can happen. When installing your PIR sensor, note that the sensor requires line of sight. So if you want the lights to come on or stay on, this type of sensor is best used for open floor plans as it can't see through or around shelves and partitions.
PIR Occupancy Sensors
Occupancy sensors turn the lights on and off automatically. This type of sensor is perfect for laundry rooms and public restrooms where you don't need the lights on all day, but don't want to manually flip a switch when entering. It is also good for small supply rooms if the sensor has line of sight and is not blocked my shelves or boxes.
PIR Vacancy Sensors
Vacancy sensors turn the lights off automatically, but will not turn on automatically when someone enters a room. Unlike occupancy sensors, this type of PIR sensor is turned on manually. These are typically used in breakrooms with large windows or offices with plenty of natural light, where the lights don't need to be on just because a person is in the space. These are also good for kid's rooms since entering the room to say goodnight won't turn the lights on, just helps make sure the lights are turned off.
PIR Occupancy/Vacancy Sensors
These PIR sensors can be set to either occupancy mode or vacancy mode. In occupancy mode, the lights turn on and off automatically. When in vacancy mode, the lights turn off automatically, but will need to be turned on manually. Because you can switch between the two settings, it offers more control over your home or commercial lighting.
If you still have questions about which technology is right for your installation, give us a call at 1-800-624-4488. One of our lighting experts is happy to walk you through everything you need for a brighter tomorrow.