The detection principle is that infrared light is transmitted to a long distance through LED infrared light emitting diode, and then focused by optical reflector and received by receiver. When the light is blocked, an alarm will be given.
Infrared ray is a kind of invisible light, which will spread to form a cone beam when projected. Infrared light emits 1000 beams per second, so it is a pulsating infrared beam. Therefore, these opposites cannot be transmitted over a long distance (within 600 meters).
Extended data:
I. Functional characteristics
1, wired, bus compatible, live holographic real-time report.
2. Dedicated DSP chip, patented multidimensional fault tolerance and true detection alarm technology.
3. Use an offset spherical high-precision optical focusing lens.
4. Intelligent power transmission. The self-developed chip can automatically sense the change of the surrounding environment and automatically adjust the transmitting power of the transmitter according to the environmental conditions, which greatly prolongs the service life of the transmitting tube and reduces the power consumption.
5, digital fuzzy artificial intelligence identification, using artificial intelligence fuzzy judgment, to minimize the false alarm rate.
6. Adjust the structure of the upper and lower optical lenses at the same time to make the adjustment faster and more accurate.
7. Full-function diagnosis and environmental adaptation.
Two. general survey
Using a detector with beam interruption? When someone crosses the monitoring protection zone, the invisible infrared beam is blocked and an alarm is triggered. Often used for outdoor fence alarm, always used in pairs: one transmitting and one receiving.
The emitter emits one or more infrared rays invisible to human eyes, forming a warning line. When an object passes by, the light is blocked, the receiver signal changes, and an alarm will be given after amplification.
The infrared crosstalk probe should choose the appropriate response time: too short is easy to cause unnecessary interference, such as birds flying by and small animals passing by; If it is too long, it will not be able to report. The shortest shading time is usually determined at the speed of 10 m/s.
If a person's width is 20cm, the shortest interruption time is 20 ms. More than 20ms alarm, less than 20ms no alarm. Infrared correlation detectors are widely used in urban security, residential areas, factories, companies, schools, families, villas, warehouses, resources, petroleum, chemical industry, gas transmission and distribution and many other fields.
References:
Baidu encyclopedia-infrared correlation alarm