Home security systems should be using a wireless or wired?
The scope of this problem involves great, but the family is concerned, our view is: If your house or your in the decoration of the house before the area is too large (in particular, Fushi structure), you have installed anti-theft system, some knowledge and experience (or you can find the help you install the technical staff), we recommend that you use wired; reason: our renovated housing, the wiring must be to transform the entire house, while adding security system particularly convenient wiring , whether ye say, wired stability is unquestionable; excessive housing (duplex structure, villas, etc.) are best to use wired because: wireless door sensor, small buttons and a small part of the wireless transmission distance detector limited, over long distances may produce false positive or false negative. The housing area was small (less than 150 square meters) of the customer, we recommend the use of wireless, because the average wireless burglar alarm system can meet the requirements of the wireless transmission; reason: the wireless system, you can always change according to your needs against regional and location, change of equipment is also very convenient. Need to be reminded of is: If it is the wired way, under the conditions permit, as much as possible cloth and place a few spare lines on confirmation of the arrangements for you by professionals. Overall: Cable product advantages, disadvantages
Advantages: because it is dedicated line, so the alarm signal transmission is relatively stable, less susceptible to interference from external factors.
Disadvantages: the impact of aesthetics, construction work volume, complex operation, maintenance inconvenient, to be hand maintenance.
Wireless products, advantages, disadvantages
Advantages: No damage to prevent the region's overall appearance, simple installation, easy to operate, to learn.
Cons: alarm signal will be subject to interference from external factors, leading to alarm signal transmission distance attenuation.
What is active infrared and passive infrared, and how the difference?
Active infrared technology commonly used in infrared perimeter shooting system, there are a variety of distance specifications. The passive infrared detectors, and can be divided into Shuangjian, three Kam and more! More use of the indoor alarm system. Infrared shooting system is constituted by the transmitting and receiving equipment, take the initiative to launch infrared wave transmitter at the receiver to receive! Passive infrared sensors are passive infrared waves emitted by the human body! In other words: can fire as active infrared infrared signals, but itself does not emit infrared signal detecting objects in the human body or a passive infrared infrared waves.
From the construction, it should be required to be consistent, try to avoid active infrared barrier material to avoid direct sunlight and so on! PIR should also avoid bright light, not by air blowing straight, and the temperature change, a place so big! Active Infrared used for outdoor perimeter alarm system (such as multi-beam infrared to the radio, infrared shooting fences, etc.)! Passive infrared multi-use in indoor home alarm system (such as infrared detectors, curtain detector, etc.)!
4 anti-theft alarm, 8, 14 Road, etc How to choose?
In this issue, many friends have misunderstood: that is a few to a few road detector alarm host, in fact, is wrong. Alarm host several roads, actually refers to several zones: for example, we have the living room as one zone, doors and windows as a defense area, the kitchen as a zone, the study zone as a bedroom as a zone, and 5-way is not the alarm must be host, we can study and bedroom 2 detectors compiled code for the same zone, so that the alarm with the 4 host also can. In fact, we put the above five zones of the detector and into a zone all the code, the alarm host by a road can be, but is unable to distinguish between alarm occurs when the specific location of the police intelligence.
We need to remind you is this: in choosing a host, they must first determine the need to guard against the number of spatial and regional demands, and then decided to host the zone and model. General should stay out of buying host 2-4 road space for future increase in defense areas and detection equipment.
How to choose the right detector?
According to guard the premises and area, select a different alarm probe. In general, windows and doors can be installed tamper switch, bedroom, living room to install infrared microwave probe and emergency buttons, glass break sensors installed windows, the kitchen smoke alarm installed.
Infrared detectors: the surface of any object due to the different heat will radiate the strength of the infrared range. Due to the different objects, they have different wavelength infrared radiation. Infrared detection is mainly used to detect invasion of the body and other moving objects, when the body into the detection region, stability constant of the thermal radiation is destroyed, resulting in a change of thermal radiation, infrared sensors after receiving amplification, processing, an alarm signal.
Microwave motion detector objects: the use of high frequency Doppler shift of radio waves as the detection means suitable for and open space or square. Microwave is a very high frequency radio waves, the wavelength is very short, easy to be the object reflected, incident and reflected waves according to frequency drift, can detect intrusion object. Infrared microwave detector: alarm system is one of the devices commonly used, its price is generally between 200 to 1,600 yuan. It works in one set of infrared and microwave. When the infrared and microwave detectors at the same time an alarm signal, the probe will have alarm output, reducing the possibility of false positives. There are several models of infrared microwave probe, corresponding to a different detection range, detection of a fan and some regional, some detect a narrow lot (such as corridors), some 360-degree detection, we must choose the right according to the specific needs of the model, so as to achieve the desired effect. The general sensitivity of the detector is adjustable.
Magnetic detector: It is a widely used, low cost, easy installation, and does not require adjustment and maintenance of the detector. Magnetic switch into moving parts and output parts. Moving parts of doors and windows installed in the activities; output unit installed in the appropriate windows and doors, the installation distance between the two does not exceed 10 mm. Output units, there are two lines, the normal state for the normally closed output, doors and windows open more than 10 mm, the output converted to normally open.
Glass break detectors: it uses piezoelectric micro tuner, installed in the location of the face of the glass, since only the sound of broken glass, high-frequency effective detection, so the glass will not be caused by the shock reaction.
Ultrasonic motion detector objects: Ultrasonic sensors require a mobile object can be sent and another is responsible for receiving ultrasonic transducer, but also receive and fired the existence of a transducer on the body. Usually fired by the transducer sends out a fixed-frequency ultrasound, scattered in the detection space, if there is an object the reflected ultrasound, the frequency shift will occur, to detect whether there are things moving. The detector is susceptible to vibration and air effects.
Infrared detectors on the radio: the use of the probe beam interdiction when someone across the way have control protection area, the interdiction invisible infrared beam and trigger alarms. Commonly used for outdoor wall alarm, it is always used in pairs: a transmitter and a receiver. Transmitter emits a beam or the human eye can not see infrared light, the formation of the warning line, there is the object passed, the light is blocked, the receiver signal changes, the alarm after amplification. Infrared sensor on the radio to select the appropriate response time: too short and easily lead to unnecessary interference, such as flying birds, small animals through so; long omission occurs. Usually 10 meters / sec to determine the minimum dark time. If the person's width of 20 cm, the minimum occlusion time of 20 milliseconds. Greater than 20 milliseconds alarm, the alarm is not less than 20 milliseconds.
Smoke alarm detector: There are two kinds of photoelectric and ion type, the former light path blocked by the smoke alarm, and the latter using its own sensors, sensing ion concentration in the air, the different perception of different gas sensors (eg gas), common is designed to fire the concentration of carbon ion smoke detection probe.
Passive infrared detector installation considerations
As a passive infrared detector is a kind of weak signal detection equipment, the installation should be noted that some of the details of issues, such as height and sensitivity. A passive infrared detector is properly installed, you must master the information in the following aspects: first, the performance characteristics of the detector must understand, then to reasonably determine the location of installation, and finally must be careful debugging. Detector can not be said to install a good alarm, then how to determine a passive infrared detector is installed it?
Determined according to the instructions to install the normal angle
Mounting height is not random, will affect the sensitivity of the detector and the effect of anti-small pets. Imagine a detector installed in the location and height of 2.5-2M high position, then the mobile object moves from the ground, cut out and dark areas of the frequency is not the same.
Glass windows and doors should not face
Passive infrared detector are on the glass doors and windows, there are two problems: First, white light interference, clearly has a strong white light PIR on suppression, but after all not 100% inhibition. So to avoid being on the glass doors and windows, to avoid light interference. Second, external doors and windows to avoid the complexity of environmental interference, such as population movements, vehicles and so on.
Not being on the hot vents or cold and heat source
The role of passive infrared detector senses changes in temperature have a close relationship. Hot and cold vents and hot and cold sources are likely to cause false alarms detectors, for some low performance of the detector, and sometimes the air flow through the windows and doors can also cause false positives.
Not easy to swing the object being
Easy to swing the object will make the microwave detector works, it also can cause false positives. Note that the illegal invasion routes of ancient purpose detectors installed sufficient to prevent the illegal invasion of criminals, in determining the installation location, you must consider the population of the main building. In fact, we prevent the entrance, cut off the illegal invasion route, it reached our goal.
A reasonable selection
Passive infrared detector with a variety of models. From 6 meters to 60 meters, to three from a single infrared technology, from wall to ceiling in there, then the women of the detector to prevent the space must take into account the size of the surrounding environment, the actual situation and the characteristics of import and export. Sometimes have to consider replacing the Fresnel lens to meet the requirements.
Debugging
After installation of the detector, the detector is the final commissioning work to be done. Passive infrared detector commissioning has two methods, one is the step test, is commissioning the region in the alert line to take the s-type range of length perception alert liberalization, from the figure we can understand that.
Sensitivity of microwave and infrared sensitivity measured by-step approach to be adjusted, the sensitivity is too high or too low will affect the preventive effect. Sometimes the change of seasons, winter and summer respectively, to adjust the sensitivity. Microwave sensitivity must not be too large, because only the penetrating microwave, in the debug time to pay attention.
The second method is measuring instruments, some with background noise detector output voltage, the voltage with a multimeter to test, when the detectors on their guard, it's the static background noise, the size of the output voltage, that the interference sources of interference level, in order to determine the suitability of the location of the installation of such detectors.
Part of the above is just a passive infrared detector for use and the basic common installation methods make a point analysis, the various brands in the infrared treatment has its unique approach, so we use the installation, you must carefully read the instructions, the most important the accumulation of experience through practical work, the characteristics of the detector will be able to understand more about, so better to play a passive infrared detector in the security role of the project.
