External RF signals, etc.
internal factor
Internally, due to the noise and interference of devices, such as the signal transient of photothermal blood release sensor. In view of the above situation, the new generation infrared detector of lane detector adopts some independent technologies to solve this kind of problem. Firstly, two photothermal sensors connected by different circuits are applied to the focus of infrared lens. The special lens divides the coverage area into a plurality of protection areas with trapezoidal sensitivity, and ensures the signal strength in the protection areas. The unique lens can also be used as an infrared filter. The black lens with special surface treatment allows visible light and short-wave infrared rays (which are found in most places with white light sources) to enter and then be absorbed by its black base. The black infrared lens only reflects the infrared ray with the wavelength in line with human movement, and then reflects it to the photothermal sensor. The detector can prevent white light interference by obtaining a patented white light filter. If someone enters or leaves one or several areas covered by the detector, the detector should be able to detect the change of infrared radiation energy. After the A/D converter digitizes the signal sent by the sensor, it is analyzed by Visatec (all-digital intelligent signal analysis technology based on fast thinking logic) signal processor, and then an alarm signal is sent out. Digitizing the signal of photothermal sensor can eliminate the transient of signal and the interference of electromagnetic wave. The decline of detection ability can be divided into several aspects:
The distribution of each detection field of view of the detector is unreasonable, such as the gap is too large.
The detector is blocked. Such as paper, clothes, etc. Foam and spray (a common means of intruders).
Because there is little difference between body temperature and environment, the detection ability decreases. Two photothermal sensors connected by different circuits are located at the focusing point of the black infrared lens.
The lens divides the coverage area into several fields of view with the same sensitivity, and ensures the signal strength of the fields of view, and the fields of view are staggered to form a compact distribution form similar to a chessboard. There are many types of detection range, which can meet the requirements of various occasions. The longest detection distance of a single machine can reach 150m, and the same model with different mirrors can realize the conversion between wide-angle and long-distance curtain detection. The general detection distance is 15m. After the product is equipped with reflector, it can reach 25m.
The working temperature is -20 ~+50℃, and the technical parameters have little influence in this range. Usually room temperature.
The shell type conforms to various standards of IP3 1-IP65 to prevent insects and airflow from entering. Among them, the outdoor type has a metal shell, which has strong protective ability and can adapt to harsh environment. Generally, it is IP3 1.
The test function has the function of working state wiring test.
Day/night state transition includes day/night state transition.
The unique design technology of detection loop (with plug) and sensor makes the installation of detector easier and easier, and it is easy to be damaged during installation.
Self-checking complete voltage monitoring electronic circuit and sensor automatic periodic self-checking function, unique anti-pet filtering function.
When solving false alarm and preventing harm, filter circuit is provided to prevent noise and sudden change of internal circuit, and the signal of photothermal sensor is digitized to eliminate signal transient. Eliminate external white light source, unique black mirror technology and white light filter, and eliminate visible light and short-wave infrared.
Eliminate external radio frequency and other signals, digitize signals and eliminate interference.
Detector shielding has a unique electronic adaptive anti-shielding function. Detect line damage, whether in withdrawal or deployment, and monitor the line around the clock. Some detectors have
Intelligent analysis Visates high-intelligence signal analysis technology, all-digital high-intelligence signal analysis technology based on fast thinking logic, and the signal processor sends an alarm signal after analysis. This process involves all the standards in detection, such as signal amplitude, time, format, energy and spectrum, plus the statistical information actually extracted from the site. These standards must be combined with judgment to test their rationality, and the detector will give an alarm only after the results meet the standards of forced entry.
In order to improve the detection ability, the sensitivity of the detection field of view is improved. At the focal point of the infrared lens, two photothermal sensors connected by different circuits are applied. The special lens divides the coverage area into several protection zones with the same sensitivity, and ensures the signal strength in the protection zones.
The field of view distribution of the detector is staggered, forming a compact distribution form similar to a chessboard.
Micro-temperature difference identification can quickly detect the micro-temperature change in the field of view through the difference method.
Intelligent temperature detection: tiny temperature changes in the field of view can be quickly detected by the difference method. Unique anti-small pet filtering function
Complete voltage monitoring
Automatic periodic self-inspection function of electronic circuits and sensors
Unique electronic circuit (with plug) and sensor separation design technology make the installation of the detector easier.
The completely sealed detector can prevent insects and airflow from entering.
Some views on dual identification detectors in Chinese mainland area
At present, Chinese mainland's dual-identification anti-theft detector (infrared+microwave) occupies a certain share in the market, but it is quite similar to the common dual-identification anti-theft detector (infrared+microwave). Dual-identification anti-theft detector (infrared+microwave) was first produced under the condition of high false alarm rate of ordinary simple infrared detector. Although the common dual-identification burglar detector (infrared+microwave) adopts the relationship between infrared alarm and microwave alarm, it also reduces the detection ability. Microwave itself has a certain penetration ability (such as walls, etc.). ), which increases the false alarm rate. Microwave can be shielded by metal, which increases the detection limit in practical applications (such as refrigerators).