There are many types of detectors in smart home systems , and the classification methods are various. Generally, the detectors can be classified according to the type of sensors, the range of detection, the transmission mode of signals, and applications. Below we will introduce separately. 1. Classified by sensor type According to the type of sensor, that is, according to the physical quantity detected by the sensor, there are usually magnetic switch detectors, vibration detectors, ultrasonic detectors, infrasound detectors, infrared detectors, microwave detectors, laser detectors, video motion detection. , gas detectors and fire detectors. (1) Classification of infrared detectors. 1 according to the working principle infrared detector can be divided into infrared detector, microwave infrared detector, passive infrared / microwave infrared detector, glass broken infrared detector, vibration infrared detector, ultrasonic infrared detector, laser infrared detector, magnetic control Switching infrared detectors, switching infrared detectors, video motion detection alarms, sound detectors, etc. 2 According to the working mode, infrared detectors can be divided into active infrared detectors and passive infrared detectors. The latter is to induce infrared rays emitted by the human body itself or the outside world. The former consists of an infrared emitter and an infrared receiver. The infrared emitter emits one or more modulated infrared rays to the infrared receiver. When there is no obstruction between the transmitter and the receiver, the detector does not alarm; when an object is blocked, the receiver output signal changes. Detector alarm. (2) Classification of gas detectors. According to the detection gas, it can be divided into combustible gas detector (portable combustible gas detector) and toxic gas detector. 1 combustible gas detector (explosion detector) can detect a variety of combustible gases or vapors according to the principle of catalytic combustion detection. 2 Toxic Gas detectors are generally electrochemical detection methods. Depending on the sensor, a variety of toxic gases such as CO, H2S, NO, N02, Ch, HCN, NH3, PH3, etc. can be detected. (3) Classification of fire detectors. According to the fire parameters to be tested, the fire detector can be divided into a smoke detector, a temperature sensitive type, a photosensitive fire detector and a flammable gas detector, a composite fire detector such as a smoke temperature, a warm light, a smoke temperature light, and the like. Image type and explosion-proof detectors, etc. For the classification of fire detectors, a smoke detector is a fire that uses a small sensor to affect the combustion and/or pyrolysis of aerosol aerosols (solid or liquid particles) suspended in the atmosphere around it. Detector. A temperature-sensing fire detector is a fire detector that uses a point or cable sensor to influence the abnormal temperature or rate of temperature rise around it. Photosensitive fire detectors are based on the characteristics of the burning flame and the light of the flame. A fire detector composed of radiation for responding to the characteristics of flame light in a fire, generally can be made into an active infrared line type fire detector and a passive ultraviolet and infrared flame detector. The combustible gas detector uses various gas sensors or The sensor responds to certain concentrations of gas in the initial fire or to the concentration of flammable gas such as liquefied petroleum gas.
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