What are PIR Sensors and How they Work?

Publish Time: 2021-05-14     Origin: Site

PIR Motion Detector is a sensor that detects the movement of the heat source object. PIR means "passive infrared". With the help of an optical system, it can detect the change of thermal radiation in a certain defense space. When a person moves in the detection area, it will cause changes in the energy of infrared heat radiation. The PIR Motion Detector converts the received change of infrared heat radiation energy between the active human body and the background object into a corresponding electrical signal, and sends out an alarm signal.


These PIR sensors are generally made up of two small slots. Think of them as "eyes". When nothing is moving in front of the sensor, the "eyes" pick up the same amount of infrared radiation. However, when a warm body enters the sensor's field of view, one of the "eyes" will pick up the movement before the other. This is because the two different parts of the sensor are picking up different heat signatures so the sensor knows there is something moving across it's field of view. And, when the warm body leaves the sensor's field of view, the heat signature drops, so the sensor returns to normal

Our PIR Detector uses a fully digital CPU processor detector to ensure the detection distance under different temperature environments and avoid false alarms caused by environmental interference. So they won't trigger whenever a leaf blows across a path or a branch moves in the wind. At the same time, IoT Wi-Fi technology is used to connect the PIR Motion Detector to the cloud server, allowing users to obtain alarm information at the first time.

DREAMLNK now is providing various Window/Door sensors, PIR Detectors for smart home use, with neutral packing, can be also customized with your own logo, contact us for more details!

What's the Difference Between SX1278/SX1276 Based Wireless Modules?

Can Si24R1 RF Module be Used to Replace Nordic nRF24L01+ RF Module?

Why Should We Choose DL-CC1310-B UART Module?

Frequently Asked Questions about SX1278 LoRa Module

How Does the LLCC68 LoRa Module Help the Sub-1Ghz Wireless Connection Market?