Analysis of technical characteristics of active infrared perimeter detector

According to different detection principles, perimeter detectors can be divided into many types, among which active infrared beam detectors are the most popular. Because they have obvious advantages over similar perimeter detectors in terms of reliability, cost price, and convenience of installation and debugging, they have become perimeter detector products that security practitioners trust. With the popularity of active infrared beam detectors in the market, some businesses, driven by profit, have reduced the quality and performance of the products themselves, resulting in the output of inferior products or even fakes in the market, causing end users to doubt the reliability of active infrared beam detectors. Here, we explain some technical characteristics of high-quality beam products.

As an outdoor device , the active infrared detector must have a certain anti-interference ability to the outdoor environmental factors. In fact, factors such as sunlight ultraviolet rays, bad weather, plants, small animals, radio frequency , and electromagnetic interference are all factors that interfere with the detector. Therefore, when choosing a high-quality professional infrared product, it is necessary to examine some of its technical characteristics:

Firstly, in terms of product stability, while controlling costs, the maximum energy output and reception at both ends of the equipment should be guaranteed. It is advisable to use the latest optical technology combining crystal spherical lens and Fresnel lens technology;

In order to resist the interference of sunlight ultraviolet rays or strong light, the detector housing must be made of special materials that filter stray light and use the optical mold process. The simplest way to detect this high-quality mold process is to observe whether the reflected image on the outer cover is deformed and whether there are burrs on the edge. In fact, this principle is the same as that of optical lenses . Deformed objects are caused by distorted optical components, and when used on detectors, it will cause energy loss;

In order to resist stray light interference, in addition to the requirements for the optical housing, excellent detectors must also use the same filter materials and processes on the optical components inside the receiving end;

In order to minimize the impact of bad weather on infrared light attenuation, the detector must have a margin of at least 10 times the distance (the domestic CCC standard is 6 times, and the international standard is generally 10-20 times);

In order to adapt to the requirements of outdoor environment, the through-beam products should have anti-frost and condensation technology, the shell must have an anti-frost and condensation groove structure design, and there should be optional heater accessories for use in low temperature environments; at the same time, the shell and threading holes must use professional waterproof technology such as rubber seals, with super waterproof, insect-proof and dust-proof performance;

In order to facilitate the users of the perimeter system to carry out important daily inspection and maintenance, it is required to be able to directly observe the various working or fault conditions of the detector without opening the shell, which will greatly facilitate system maintenance;

Since branches, fallen leaves or flying birds are smaller than human bodies, they can generally only block one beam. To eliminate false alarms caused by interference from plants or small animals, the equipment must use at least two beams. To ensure the effectiveness of two-beam detection, the optical structure design requires that the distance between the upper and lower beam centers should be no less than 70mm. In this way, the characteristic of multi-beam detectors that they must be blocked at the same time before they can alarm can be used to effectively prevent false alarms.

With adjustable light blocking time, the blocking time of falling leaves or flying birds is usually shorter than that of people climbing the wall, because the speed of the former is faster. Through this measure, the perimeter system can effectively distinguish false alarms;

To facilitate stacking installation or avoid interference, a good product series should have both ordinary fixed frequency and digital frequency conversion options;

The optical axis calibration of the through-beam is very important. High-quality through-beam products generally have two or more of the existing sensitivity voltage calibration, LED indicator, sound calibration and other technologies in the industry. At the same time, in order to facilitate on-site installation and future daily maintenance, it is now required to use an integrated aimer to prevent loss.

According to survey data , more than 50% of the faults of the beamforming device are caused by lightning or power surges. In order to prevent damage to electrical equipment and false alarms caused by other than direct lightning strikes, the lightning protection index of the beamforming product itself is very important. Of course, more importantly, the perimeter system loop must also have a grounding design that is lightning-proof, magnetic-proof, and radio frequency interference-proof.