How to choose the right detector?
Add Date：2023/3/20 Hits：4885 Font Size：S M L Back
According places and regions to guard against, and choose different alarm probe. In general, the doors can be installed tamper switch, bedroom, living room to install infrared microwave probe and emergency buttons, windows broken glass sensor installation, kitchen installation of smoke alarms.
Infrared detectors: any object because of different surface heat will radiate strength ranging from infrared. Due to different objects, infrared radiation wavelengths they also vary. Infrared detection means for detecting the main body and the other moving object intrusion, when the body enters the detection area, the stability constant of the thermal radiation is destroyed, resulting in a change in the thermal radiation, the infrared sensor to receive the amplified processed, an alarm signal.
Microwave object motion detectors: the use of high-frequency radio waves to detect the Doppler shift as a means for the open space or plaza. Microwave is a very high frequency radio wave, the wavelength is very short, easily reflected by the object, according to the frequency shift of the incident and reflected waves, can be detected invaded objects.
Infrared microwave detectors: alarm system is one of the commonly used equipment, its price is generally between 200 to 1600 yuan. It works on a set of infrared and microwave. When the infrared and microwave detectors at the same time there is an alarm signal, the probe will have alarm output, reducing the possibility of false positives. Infrared microwave probe a variety of models, corresponding to different detection range, some detect a fan area, and some detect a narrow area (such as corridors), some 360-degree detection, must be based on the specific needs to choose the right model, so as to achieve the desired effect. General sensitivity of the detector can be adjusted.
Magnetic probe: is a widely used, low cost, easy to install and does not require adjustment and maintenance of detectors. Magnetic switches are divided into movable member and the output member. Movable member is mounted on the movable doors and windows; output member is mounted on the respective doors and windows, installation of both distance not more than 10 mm. There are two lines, the normal state is normally closed output, doors and windows open more than 10 mm, the output is converted into a normally open output components.
Glass breakage detector: it uses a piezoelectric micro damper, installed in a position facing the glass, since only the sound of breaking glass of high frequency effective detection and therefore are not subject to vibration of the glass itself and to cause a reaction.
Ultrasonic motion detector object: Ultrasonic perceive moving objects needs to be able to send an ultrasound and another responsible for receiving transducer, but also to receive and transmit transducer co-exist on a body. Usual transducer transmitting the ultrasonic wave is transmitted at a fixed frequency space spreading in the detection, if there is a ultrasonic wave reflected by the object, whose frequency is shifted, thereby to detect whether moving objects. The detector is easily affected by vibrations and airflow.
Infrared detectors: the detector using a beam blocking the way when someone crosses over the protection zone monitoring, interdiction invisible infrared beam and trigger an alarm. Commonly used in outdoor fence alarm, it is always used in pairs: a transmitter, a receiver. The transmitter emits a beam of infrared light or the human eye can not see, the formation of the cordon, there are objects via light is blocked, the receiver signal changes, amplified alarm after treatment. Infrared shooting probe to select the appropriate response time: short easy to cause unnecessary interference, such as the bird flew through the small animals such as; too long will omission occurred. Usually at a rate of 10 m / sec to determine the shortest time shading. If the width of 20 cm human, the minimum cutoff time of 20 ms. Greater than 20 msec alarm, the alarm is not less than 20 milliseconds.
Smoke detectors: a photoelectric type and the ion type two, the former is the use of blocking optical smoke alarm, the latter using its own sensors, sensing the concentration of ions in the air, a different perception of different gas sensors (such as gas), commonly used is designed to detect fire carbon ion concentration smoke detector.
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