Little knowledge of the alarm
[ 2012-10-26 | The latest news | Administrator | Read the number of：4892 ]
1 What is the anti-theft alarm system?
Anti-theft alarm system detector using various types of functionality into the household housing surrounding space, the environment and people
Row overall protection system.
What is detector?
Current, pulse signal detector is the use of sensors sensing various physical changes, chemical changes generated
To promote the RF circuit to emit an alarm signal.
3, burglar host role and work
The host is the core of the system. Is used to receive the probe sent to the alarm signal, while a timely feedback
; Alarm signal is received, the host will produce high-decibel siren sound at the same time with the telecommunications network outward
Alarm phone call groups set by the master himself.
4, passive infrared intrusion detectors
Passive infrared detector according to body * passive absorption heat animal activities emit infrared heat
Alarm, also known as the pyroelectric infrared sensor, the detector itself does not emit infrared
5, the basic concept of the passive infrared detectors infrared detection
Within the warning area, and why people move passive infrared detectors to alarm signals in it?
In nature, any objects above absolute temperature (- 273 degrees) will produce the infrared spectroscopy, different temperature
Of the object, the wavelength of the infrared energy that its release is not the same, therefore the infrared wavelengths and the temperature level is relative
Off.
There are two key components in passive infrared detectors, a pyroelectric infrared sensor (PIR)
Can wavelengths between the infrared signal in the 8-12um change into an electric signal, and on the nature of the Bai Guangxin
Inhibit, passive infrared detectors alert area, when human movement, pyroelectric red
External sensor is sensitive to the background temperature into the warning area, when the body is through the Fresnel lens, pyroelectric red
The outer sensor sensitive to the difference signal of the body temperature and the temperature of the background is, therefore, the infrared detection of the infrared detector
Measurement of the basic concept is to sense the temperature difference of the moving object and the background object. Another device is the Fresnel
Seoul lens, there are two forms of the Fresnel lens, refractive and reflective. Fresnel lens there are two: First, the role of
Focusing effects, coming pyroelectric infrared signal refraction (reflection) in the PIR, the second role is to alert region stars
A number of the bright areas and dark areas, so that the moving object into the alert area can produce varying the form of the temperature change in the PIR
An electrical signal of pyroelectric infrared signal, so that the PIR can generate change
6 What is the detection range?
The detection range of the detectors work properly sensing range, i.e. the detector is able to detect less than in this range all
The object motion thereby generating an alarm state.
What is the detection range?
Detector that can be detected in the normal work of the most remote.
What is the firing distance?
Wireless devices in the wireless alarm signal is triggered after the alarm system in the form of electromagnetic waves launched out farthest
Distance.
9 What is the sensor sensitivity?
, From the detectors are triggered alarm detection distances and the speed of reaction speed, high sensitivity induction
Detector very far distance can be detected, the sensitivity is low, and can only detect the close range.
10, passive infrared detectors, installation considerations
Passive infrared detectors are a weak signal detection equipment, the installation must pay attention to some details.
Aspects, such as height, sensitivity, etc.. Properly install a passive infrared detector, you must master the following
Aspects: First, the performance characteristics of the detector must be aware of, and secondly to reasonably determine the location of the installation,
Finally, it must be carefully debugging. Can not say that the detector alarm instructions to install, and then how to determine a is
Dynamic infrared detector installation location?
* According to the manual to determine the normal installation angle
Mounting height is not random, it will affect the sensitivity of the detector and the effect of anti-small pets. Imagine a
A detector mounted on the 2M height position and the height position, then the moving object from the ground when moving, cut
The frequency of the bright areas and dark areas are not the same.
* Should not be the face of the glass doors and windows
Passive infrared detector is on the glass doors and windows, there are two problems: First, the white light interference, apparently to PIR on white with
Strong inhibitory function, but, after all, is not 100% inhibition. Therefore, to avoid being strong glass doors and windows can be avoided
Light interference. The second is to avoid complex environmental disturbance outside the doors and windows, such as the flow of the crowd, the vehicle.
* Should not be is on the hot and cold air vents or cold and heat source
The induction effect of the passive infrared detector has a close relationship with the change in temperature. Hot and cold vents and cold and heat source
Detectors are likely to cause false positives, some low performance of the detectors, and sometimes through the doors and windows of the air convection
Cause false positives.
* Easy to not being on the swinging object
The easy swinging objects will microwave detector works, so the same may cause false positives. Ancient attention to illegal entry
Invasion route
The purpose of the detector is installed enough to prevent the illegal invasion of criminals must be considered before determining the location of the installation,
The buildings mainly to the population. In fact, we prevent the entrance to truncate the illegal invasion of line, it reached
Their purpose.
11 Active Infrared Beam Intrusion Detector
Active infrared transmitter from the transmitter, infrared receiver by the receiving end to form a mesh of infrared. This exploration
Detector capable of invading prevention initiative, not through small pets or climate mistaken
Alarm conditions, thereby reducing the rate of false positives to the greatest extent.
12, what is the wired and wireless?
Alarm signal transmission mode: wired and wireless type. Detector detected the illegal intruder
Wireless detector alarm signal to alarm host in two ways, through the hair of a certain frequency of electromagnetic waves
Transmit alarm signals, the wired type detectors are divided into the switching signal output and the level signal output.
13, wired burglar wireless burglar distinction
A wired product's strengths and weaknesses
Advantages: because it is a special line dedicated alarm signal transmission is relatively stable and less susceptible to the interference of the external factors.
Disadvantages: heavy workload affect the appearance, construction, complex operation, maintenance inconvenience, to be someone to maintain.
The advantages and disadvantages of the wireless products
Advantages: prevent the region will not disrupt the overall appearance, simple to install, easy to operate, the elderly, children, a study will be.
Disadvantages: The alarm signal will be the interference of external factors cause alarm signal transmission distance attenuation
14, door magnetic detector? The working principle is what?
Door magnetic detector is used to sense the doors and windows open and close. Usually wooden door magnetic, magnetic window shutter door sensor, iron gate magnetic.
The principle is to use the magnet can control the opening and closing control magnetron principle, when both * rope together when the magnetron was
Closed state, and then the two separate magnetron will disconnect disconnect signal triggers issued by the RF circuit
The line alarm signal to the alarm host.
15, what a smoke detector? The working principle is what?
Smoke detectors used in the home, office, and commercial area. The scene early fire smoke timely.
An alarm and take preventive measures. Usually divided into the ion-type smoke and photoelectric smoke. Ionization type smoke its original
The rationale is to use the principle of smoke particles in the inter-electrode voltage between the electrodes will change.
16 What is a gas detector? The working principle is what?
Mainly installed in the kitchen, to effectively prevent gas leak endanger the life of the owner. Its front end of the sensor probe to the gas
When the temperature changes, the process of the change through the processing circuit into a control signal to trigger the alarm signal.
Networking center host communications by what means?
Two ways: 1, the monitoring center and host by Telecom's telephone lines to communicate with, it does not affect the normal telephone communication
Words.
