With the continuous development of social economy, people’s life is improving day by day, people pay more and more attention to the safety of family life and property. According to the different anti-theft area, all anti-theft alarm can be divided into indoor anti-theft alarm and outdoor burglar alarm two categories. Indoor burglar alarm, as the name implies, is installed indoor with various alarm devices. Because the indoor environment is relative stable, subject to fewer external interference, so from the stability feature,indoor burglar alarm false alarm rate is lower than the outdoor burglar alarms. However, because the indoor area is the place where the home owner often moves, it is necessary to frequently arm/disarm the control panel to avoid false alarm from home owner activity. Moreover, consider from the anti-theft side, indoor detectors will cause alarm only when intruders break into the room, and it may be more harmful because of panic. Different from the indoor burglar alarm, outdoor anti-theft alarm installed outdoors and alarms before the intruders enter into the house, so as to scare away the theft and avoid the loss. However, due to the outside installation, there are more requirements for the detectors such as waterproof and extreme weather resistance, free false alarm from sunlight interference and falling leaves etc.
Commonly used outdoor detectors and characteristics are as below:
I.Electronic fences:
Electronic fences can be divided into: pulse electronic fences, tension electronic fences and pulse tension electronic fences.
The advantages of electronic fence are:
1.Low false alarm rate.
2.Good environmental adaptability, can be installed on different terrain.
3.High deterrent force.
The disadvantages are:
1.High cost of construction.
2.The resulting pulse voltage may cause harm to children and the elders.
3.It can not be installed in flammable and explosive locations.
4.It is easy to let you feel in a cage, and easy to let the rattan plant growing.
II.Wired infrared beams
It is the photoelectric infrared beam using the cable for power supply and signal transmission.
The advantages of wired infrared beams:
1.The use of cable transmission is not easily disturbed by the outside environment interference.
2.Because of the wired power supply, the infrared distance is relatively far.
3.The impact of environmental factors is less.
However, there are also many disadvantages of wired infrared beams.
1.Need to dig ditch for wiring, long construction time.
2.High labor costs.
3.With big trouble for system maintenance later.
4.Cables are vulnerable to aging and gnawing by rodents
5.Due to long-term powered, components are easy aging and leading to short service life.
6.Vulnerable to lightning strikes leading to system paralysis.
III.Solar power wireless photoelectric beam system
The solar power total wireless infrared beam system is an upgrade product of wired infrared beam system. The use of solar panels to power the beam, the use of wireless modules for wireless FM, and even frequency hopping transmission make the beam no wiring.
In addition to the advantages of wired beam, the solar power wireless beam also has below advantages:
1.Convenient and short time construction.
2.Easy maintenance in later period.
3.No damage to affect the original building structure, decoration.
4.The use of dot injection technology to extend the life of components and equipment.
5.Less affected by lightning strikes.
Of course, solar power wireless beam also has disadvantages.
1.The installation environment has certain requirements.
2.Susceptible to metal structures and high voltage equipment.
3.Susceptible to wireless co-frequency interference.
4.Equipment price is higher than wired beam.
5.Due to different wireless frequencies and different transmission protocols, the system compatibility is not strong.
Now there is a kind of solar wireless infrared transmission on the market using frequency hopping technology to transmit signals, so as to increase the original characteristics of wireless anti-jamming ability, to solve the problem of the same frequency wireless signal interference.
IV.Solar power wireless light wall
Solar power wireless infrared light wall is a supplement of solar power infrared beams. Because infrared beam is basically two beams and three beams, in some special occasions, such as no wall open area, entrance and exit etc. large areas of protection, it needs infrared light wall for security protection. Due to its own protection height of about one meter or more, infrared light wall can be installed in the above areas and prevent intruders to climb or jump over. Moreover, the solar power wireless light wall has built-in horn to scare away the intruders and increase deterrent force. There are 4 beams, 6 beams, 8 beams and 8 beams with garden lamp of wireless solar power infrared light wall.
V.Vibrating fiber optic cable
The system uses optical fiber as the intrusion detection unit.
It has the following advantages:
1.Not need electricity supply, belongs to passive detectors, effectively avoid lightning interference
2.Its single defense area distance up to 500-1500 meters and it is suitable for wide perimeter protection.
3.Compared with the electronic fence, the construction is simple, no digging cable trench, direct laying can be done, and is not affected by the complex terrain;Very suitable for the airport, chemical enterprises, petroleum pipelines, railways, residential areas and various key areas of intrusion prevention requirements.
Although vibration fiber has very significant advantages, but his disadvantages are also obvious:
1.The need to pull fiber, the overall cost and construction difficulty is still higher than infrared beams.
2.The distance of each defense area is too large, even if the intrusion is known, it is difficult to locate the specific intrusion location.
3.Real service life is not long, rain and snow corrosion is easy to increase fiber resistance, fiber becomes particularly sensitive, later the false alarm rate rises sharply.
VI.Induction cables
Induction cables include vibration cables and leakage cables. The induction cables will emit electromagnetic waves and form the defense area, when someone enters into this area, it will cause disturbance and alarm signal will be sent.
Electrostatic induction cable has the advantages of pulse electronic fence to block intruders, but also has the advantages of relatively simple installation, convenient wiring, strong adaptability to climate, temperature environment, etc..
But the disadvantages are equally huge:
1. Cables are prone to electric shocks, which in severe cases can paralyze the entire system.
2. Its cost is the highest of all perimeter alarm products.
3. The cable is susceptible to electromagnetic interference.
Because of its expensive cost, the main application sites only lie in border line security, communication fiber optic cable protection, airports, oil and gas storage and transportation, prisons, chemical enterprises, oil pipelines, railways and other state organs etc. key areas.
Outdoor zone detectors
I.Radar detector
Radar detector is designed to detect the above-level radar waves and use sound, light to scare away the intruder.
Radar detectors have the advantage of being small and not easily discovered by intruders. And the use of radar principle, can reach 360 degrees of all-round protection. It has strong penetration and can penetrate the general wooden barrier for detection. The disadvantage of radar detectors is that they are susceptible to clutter and have high requirement of the mounting area. Because as long as there is an object moving in the detection area , it will trigger alarm. So it should be installed on a stable base and the detection area is relatively stable, there is no frequent object movement.
(2) Outdoor infrared detector
Wired outdoor infrared detector
Wired outdoor infrared detector used to detect intrusion via infrared thermal radiation of moving object.
The advantages of wired outdoor infrared detector is:
1.Power supply is stable and without low power problem.
2.Size is small with good concealment, not easy to be found and destroy.
However, the wired passive infrared detector also has the following disadvantages:
1.The signal amplitude is small, easy to be disturbed by various heat sources, light sources.
2.Poor penetration, the infrared radiation of the human body is easy to be blocked and not easy to be received on the receiver beam side.
3.When the ambient temperature is close to the human body temperature, the detection sensitivity decreases obviously, sometimes causing short-term failure.
4.The main direction of motion detected is the transverse direction of motion, and the ability to detect objects moving in the radial direction is poor.
5.The wiring may destroy the original decoration, later maintenance is more troublesome.
Wireless outdoor detector
Wireless outdoor infrared detector is upgraded from the wired outdoor infrared detector. Battery power supply and wireless transmission module is used for the detectors.
The advantages of wireless passive infrared detector:
1.Easy to install, no wiring needed.
2.No wiring and no destroy of house decoration.
3.Easy for maintenance.
Although the wireless outdoor infrared detector has significant advantages, but its disadvantages are also obvious:
1. Need to replace the battery regularly. At least once a year need to replace one battery.
2. Infrared detector wireless alarm signal is easy to be interfered with, for example, multiple detectors are installed nearby, then the wireless signal sent by the detectors will interfere with each other and the receiver alarm panel can not receive the alarm signal.
3. The wireless signal transmission distance is relatively short, generally around 100 meters, if there is a wall block and metal objects influence, the wireless transmission distance will be closer.
Light energy hopping frequency wireless outdoor infrared detector
This is a new product, first of all, it uses light energy combined with the battery to power the outdoor infrared detector, solved the problem of outdoor passive infrared detector power supply. No need wiring or frequent battery changes. And secondly, it uses the wireless signal transmission method of frequency hopping, solves the problem of wireless signal interference between ordinary outdoor infrared detector, from a technical level it has indeed made disruptive progress. However, to make this kind of products stable, the manufacturer’s research and development and production requirements are relatively high. Only a few relatively professional alarm manufacturers in the market has the products in the production and sales.
Its advantages: 1, light energy combined with the battery power supply greatly improved the usage of outdoor infrared detector cycle. It will use natural light for power supply, or use battery power when there is no natural light.
2, It adopts frequency-hopping wireless signal transmission technology to solve the problem of wireless signal interference between ordinary wireless outdoor infrared detectors. The frequency-hopping technology enables the wireless signal to send out via multiple channels when moving object is detected. So even if one of the channel is disturbed, the alarm signal still can be sent out to the alarm receiver timely and stably via other channels.
3.The wireless transmission has longer distance and better penetration.
Although this kind of light energy hopping frequency wireless detector has a lot of progress compared with wired detector and wireless detector, but it still has some advantages: Firstly, the price is relatively high, because of the addition of some additional components and materials, and the lack of competition of these new products. Secondly, The compatibility is not strong, because the frequency hopping technology is designed to prevent interference between wireless signals, so it is not directly compatible with the other alarm system.
Motion detection function of surveillance camera
Now most cameras are with function of motion detection and alarm. It compares the monitoring screen to determine whether there is an intrusion. Professional motion detection surveillance camera is with less false alarm and faster response, but the product is very expensive. The relatively low price surveillance camera with motion detection alarm will have high rate false alarm. Because it uses the current picture and the comparison of the last screen to determine whether there is an intrusion, so even a leaf can trigger alarm.
With the development of science and technology, now there are more and more types of outdoor anti-theft equipment. Each manufacturer’s products also have their own advantages and disadvantages, users should choose the corresponding alarm equipment according to the location and environment security needs.