Infrared sensor principle
June 16,2022
infrared motion sensor price,infrared motion detector sensor,infrared beam motion detector
The infrared motion detector sensor is a kind of sensor that uses infrared rays to process data, and has the advantages of high sensitivity. The infrared sensor can control the operation of the drive device. Infrared sensors are commonly used in non-contact temperature measurement, gas composition analysis and non-destructive testing, and are widely used in medicine, military, space technology and environmental engineering. For example, infrared sensors are used to measure the thermal image of the surface temperature of the human body from a long distance, and the parts with abnormal temperature can be found.
Infrared is a kind of light invisible to the human eye, so it has all the properties of all rays of light. But at the same time, infrared also has a very significant thermal effect. All substances above absolute zero, or -273°C, can produce infrared light. According to different emission methods, infrared sensors can be divided into two types: active and passive.
The transmitter of the active infrared beam motion detector emits a modulated infrared beam, which is received by the infrared receiver, thereby forming a warning line composed of infrared beams. When it is blocked by leaves, rain, small animals, snow, sand, and fog, the alarm should not be reported, and the alarm will be issued when people or objects of a considerable size are blocked.
Active infrared detector technology mainly adopts one transmitter and one receiver, which belongs to linear prevention. Now it has developed from the original single beam to multi-beam, and it can also double transmitter and receiver to minimize the false alarm rate, thereby enhancing the stability of the product. sex, reliability.
Since infrared is a detection medium with good incoherence of environmental factors (for sound, lightning, vibration, various artificial light sources and electromagnetic interference sources in the environment, it has good incoherence); it is also a product with good coherence of target factors ( Only the target that blocks the infrared beam will trigger the alarm), so the active infrared sensor will be further promoted and applied.
Passive infrared beam motion detector works by detecting infrared rays emitted by the human body. The sensor collects the infrared radiation from the outside world and concentrates it on the infrared sensor. Infrared sensors usually use pyroelectric elements, which will release charges when receiving infrared radiation temperature changes, and generate an alarm after detection and processing.
This sensor is aimed at detecting human radiation. Therefore, the radiation-sensitive element must be very sensitive to infrared radiation with a wavelength of about 10 μm. In order to be sensitive to the infrared radiation of the human body, its radiation surface is usually covered with a special filter, so that the interference of the environment is obviously controlled.
A passive infrared sensor consists of two pyroelectric elements connected in series or parallel to each other. Moreover, the polarization directions of the two electrodes are opposite, and the background radiation of the environment has almost the same effect on the two pyroelectric elements, so that the electric discharge effects cancel each other out, so the detector has no signal output.
Once the intruder enters the detection area, the infrared radiation of the human body is focused by part of the mirror and received by the pyroelectric element, but the heat received by the two pyroelectric elements is different, and the pyroelectricity is also different, which cannot be offset. After signal processing And call the police.
Infrared motion sensor price,infrared motion detector sensor,infrared beam motion detector, infrared sensor is a kind of sensor that uses infrared to process data, it has the advantages of high sensitivity, infrared sensor can control the operation of the drive device. Infrared sensors are commonly used in non-contact temperature measurement, gas composition analysis and non-destructive testing, and are widely used in medicine, military, space technology and environmental engineering.