What are PIR sensors?
PIR (passive infrared radiation) sensors perceive the movement of heat detected by a movable human body. Passive means that the device simply responds to the received radiation rather than actively sending a signal or scanning of the area. Implementing the incoming thermal signal are PIR sensors with very sophisticated devices with many applications. These materials are similar to photoelectric materials used in solar cells, but respond more to heat than light. Other materials used are nitrate Cesia and lithium tantalite. However, it must be connected to the electrical system to send the signal after activation. The electrical system can be operated with battery and still undetectable. This silent behavior makes PIR sensors ideal for multiplication, such as protection of valuables or restrictions on access to danger areas. Adding filters in front of the device usually stops these wrong signals. Infrared filters stop radiation of heat that is not in the same range of wavelengths as ROZsah issued from the human body.
Fresnel lens, which consists of a series of concentric grooves on a transparent surface, allows a wider field of detection and breaks incoming radiation into zones. By activating multiple areas of pyroelectric material, Fresnel's lens sensitivity of PIR sensitivity increases. Detection of heat change from one zone to another ensures that the heat source moves. The PIR sensor signal is sent to a comparator that checks the inclusion of shelters to be ignored.
Common PIR sensors include checking the room and door opening. They are ideal for the detection of someone entering a secure area and have been combined with cameras activated signals to capture the pictures of the intruder. Advanced PIR sensors allow users to control devices as diverse as sales vending machines, walking displays and escalators. Their apparent useIn the area of safety, it has spread to include energy and advertising markets. Combined with other sensors and camera systems, PIR sensors can be used in traffic control systems monitoring of transportation, hazardous conditions and traffic -infringers.