Questions and answers about the optional installation of the alarm

Misunderstanding about product insurance

Recently, many friends asked if our products have insurance. Please note that many companies claim that their products are sold with insurance. Please be careful not to be blinded. The manufacturer buys product liability insurance. Instead of family property insurance (please note: family property insurance does not accept off-site insurance, manufacturers claiming that they have purchased family property insurance are definitely fraudulent subsidiaries, even if their insurance number is true, it also belongs to joint fraud with bad insurance companies behavior).

When can product liability insurance be compensated? Please see the following terms:

The fire, explosion and life casualties caused by the quality of the product itself can be compensated.

Anti-theft alarm products are almost all weak current products, how much is the possibility of an accident? It can't be said that it is completely absent, at least much lower than that by plane. Can I be compensated if the stolen incident occurs because of the quality of the product itself? Certainly not! (From the HCZ Security Forum szlhmn burglar alarm ten trap product insurance articles)

Should the home anti-theft system use wireless or wired?

This problem involves a wide range, but as far as the family is concerned, our view is: if your house is before renovation or your house area is too large (especially the duplex structure), you have a certain knowledge of the installation of anti-theft system And experience (or you can find a technician who assists you in installation), we recommend that you use the wired method; the reason is: when we renovate the house, we must transform the wiring of the entire house, and it is particularly convenient to add the wiring of the security system No matter how it is said, the stability of the wired method is undoubted; oversized houses (duplex structures, villas, etc.) are also best to use wired, because of: wireless door sensor, small buttons and some small detectors wireless transmission distance Limited, too long distance may produce false positives or false negatives. For customers with a small housing area (less than 150 square meters), we recommend using the wireless method, because ordinary wireless anti-theft alarm systems can meet the requirements of wireless transmission; the reason is: you can change the protection area at any time according to your needs. And location, the increase and decrease of equipment is also very convenient. It should be reminded that if it is a wired method, as many conditions as possible, lay as many spare lines as possible and arrange for you by a professional on the location confirmation.

In general, the advantages and disadvantages of wired products:

Advantages: Because it is dedicated to dedicated lines, the alarm signal transmission is relatively stable and not easily interfered by external factors.
Disadvantages: Affects the appearance, large construction workload, complicated operation, inconvenient maintenance, and requires special maintenance.

Advantages and disadvantages of wireless products:

Advantages: Will not damage the overall beauty of the prevention area, simple installation, easy operation, just learn.
Disadvantages: The alarm signal will be interfered by external factors, resulting in attenuation of the transmission distance of the alarm signal.

What is active infrared and passive infrared, and how is it different?

Active infrared technology is generally used in perimeter infrared radiation systems, with a variety of distance specifications. The passive infrared detector can be divided into double, triple and so on! Mostly used in indoor alarm systems. The infrared cross-fire system is composed of transmitting and receiving equipment. The transmitting end actively emits infrared waves and receives it at the receiving end! Passive infrared is the passive induction of infrared waves emitted by the human body! That is to say: those that can emit infrared signals are called active infrared, and they do not emit infrared signals but detect infrared waves of human bodies or objects to become passive infrared.

In terms of construction, the requirements should be consistent. Active infrared should try to avoid obstacles and direct light, etc.! Passive infrared should also avoid strong light, not directly blown by airflow, and places with large temperature changes, etc.! Active infrared is mostly used in outdoor perimeter alarm systems (such as multi-beam infrared radiation, infrared radiation fence, etc.)! Passive infrared is mostly used in indoor home alarm systems (such as infrared detectors, curtain detectors, etc.)!

How to choose the alarm zone?

On this issue, many friends have misunderstood that it is wrong to think that it is necessary to use several alarm hosts for several detectors. The several ways of the alarm host actually refer to several defense areas: for example, we use the living room as a defense area, the doors and windows as a defense area, the kitchen as a defense area, the study as a defense area, and the bedroom as a defense area, and It is not necessary to have a 5-channel alarm host. We can program the two detectors in the study and bedroom as the same zone code. In this way, a 4-channel alarm host can be used. In fact, we combined all the detectors of the above five defense zones into one zone code, and a 1-channel alarm host can also be used, but it is impossible to distinguish the specific location of the alarm during the alarm.

We need to remind everyone that when buying a host, you must first determine the number and requirements of the space and area to be guarded against, and then decide the defense zone and model of the host. Generally, more than 2-4 channels should be reserved when purchasing the main unit, so as to add defense zones and detection equipment in the future.

How to choose the right detector?

Choose different alarm probes according to the place and area to be prevented. In general, doors and windows can be installed with magnetic switches, infrared microwave probes and emergency buttons in bedrooms and living rooms, glass break sensors in windows, and smoke alarms in kitchens.

Infrared detector: Any object will radiate infrared rays with different strengths due to different surface heat. Due to different objects, the infrared wavelengths radiated by them are also different. Infrared detection is mainly used to detect the human body and other invading moving objects. When the human body enters the detection area, the stable thermal radiation is destroyed, producing a changing thermal radiation. After receiving, the infrared sensor is amplified, processed, and sends an alarm signal.

Microwave object motion detector: the use of Doppler frequency shift of high-frequency radio waves as a detection method, suitable for open spaces or squares. Microwave is a kind of radio wave with very high frequency and short wavelength. It is easy to be reflected by objects. According to the frequency drift of incident wave and reflected wave, it can detect invading objects.

Infrared microwave detector: It is one of the commonly used equipment in the alarm system, and its price is generally between 200 ~ 1600 yuan. Its working principle combines infrared and microwave. When the infrared and microwave detectors have alarm signals at the same time, the probe will have an alarm output, reducing the possibility of false alarms. There are many models of infrared microwave probes, corresponding to different detection distances. Some detect a fan-shaped area, some detect a narrow and long section (such as a corridor), and some detect 360 degrees. You must select the appropriate model according to specific needs. Achieve the desired effect. The sensitivity of the detector is generally adjustable.

Door magnetic detector: It is a widely used detector with low cost, easy installation and no adjustment and maintenance. Door switch is divided into movable parts and output parts. The movable parts are installed on movable doors and windows; the output parts are installed on the corresponding doors and windows, and the installation distance between the two is not more than 10 mm. There are two lines on the output part, the normal state is normally closed output, the door and window are opened more than 10 mm, and the output is converted to normally open.

Glass break detector: It uses a piezoelectric microphone installed at the position facing the glass. Because it only effectively detects the high-frequency glass break sound, it will not be affected by the vibration of the glass itself.

Ultrasonic object motion detector: The ultrasonic object motion sensor needs a transducer that can send ultrasonic waves and another responsible for receiving. There are also receiving and transmitting transducers co-existing on a body. Transducers used for normal transmission send a fixed frequency of ultrasonic waves scattered in the detected space. If there is an ultrasonic wave reflected back by an object, its frequency will shift, thereby detecting whether there is an object moving. The detector is susceptible to vibration and airflow.

Infrared beam detector: a detector that uses a beam-blocking method to block an invisible infrared beam when someone traverses the monitoring protection zone and trigger an alarm. Commonly used for outdoor fence alarms, it is always used in pairs: one transmit and one receive. The transmitter emits one or more beams of infrared light that cannot be seen by the human eye, forming a warning line. When an object passes through, the light is blocked, the receiver signal changes, and the alarm is processed after amplification. The infrared response probe should choose the appropriate response time: too short will easily cause unnecessary interference, such as small birds flying over, small animals passing through, etc .; too long will miss reports. The minimum shading time is usually determined at a speed of 10 meters / second. If the width of the person is 20 cm, the shortest interruption time is 20 ms. Alarms greater than 20 ms, no alarms if less than 20 ms.

Smoke alarm detector: There are two types of photoelectric type and ion type. The former uses smoke to block the optical path to send an alarm, while the latter uses its own sensor to sense the concentration of ions in the air. Different sensors sense different gases (such as gas). It is a smoke sensor for detecting the concentration of carbon ions for fire protection.

Precautions for installation of passive infrared detectors:

Because the passive infrared detector is a weak signal detection device, attention must be paid to some details in the installation, such as height and sensitivity. To correctly install a passive infrared detector, you must master the following information: first, you must understand the performance characteristics of the detector, second, you must reasonably determine the installation location, and finally you must carefully debug. It can't be said that the detector can alarm to indicate that it is installed, so how to determine the installation position of a passive infrared detector?

  Determine the normal installation angle according to the manual

The installation height is not random, which will affect the sensitivity of the detector and the effect of preventing small pets. Imagine that a detector is installed at a height of 2M and a height of 2.5. When a moving object moves from the ground, the frequency of cutting the bright and dark areas is different.

Not suitable for facing glass doors and windows

Passive infrared detectors are facing glass doors and windows, and there will be two problems: One is white light interference. Obviously PIR has a strong suppression function for white light, but it is not 100% suppression after all. Therefore, avoid facing the glass doors and windows, which can avoid the interference of strong light. The second is to avoid complex environmental interference outside the doors and windows, such as crowd movement and vehicles.

Should not face the cold and hot vents or cold and heat sources

Passive infrared detectors have a close relationship with the temperature change. Both hot and cold vents and hot and cold sources may cause false alarms of the detector. For some low-performance detectors, sometimes the air convection through the doors and windows will also cause false alarms.

It is not appropriate to face the object that is easy to swing

Objects that are susceptible to swing will make the microwave detector work, and therefore may also cause false alarms. It is important to note that the purpose of installing detectors on illegal intrusion routes is to prevent illegal intrusion by criminals. Before determining the installation location, it is necessary to consider the main population of buildings. In fact, we have prevented entrances and exits, and intercepted illegal intrusion lines, which has served our purpose.

Reasonable selection

Passive infrared detectors have various models. From 6 meters to 60 meters, from single infrared to three technologies, from wall-mounted to ceiling-mounted, then the detector of the women's clothing must consider the actual conditions such as the size of the space, the surrounding environment, and the characteristics of the entrance and exit. Sometimes it is necessary to consider replacing the Fresnel lens to meet the requirements.

debugging

After installing the detector, commissioning the detector is the last thing to do. There are two methods for debugging the passive infrared detector. One is the walk test. That is, the debugger walks the s-shaped line in the warning zone to perceive the length of the warning range to be equal.

The microwave sensitivity and infrared sensitivity should be adjusted separately through the walk test method, too high or too low sensitivity will affect the prevention effect. Sometimes due to seasonal changes, the sensitivity must be adjusted separately in winter and summer. Microwave sensitivity must not be too large, because microwaves are only penetrative, so pay attention when debugging.

The second method is instrument measurement. Some detectors have a background noise voltage output interface. Use a multimeter to test the voltage. When the detector is in the alert state, its static background noise output voltage indicates the interference of the interference source. Degree to determine whether this type of detector is suitable for installation at this location.

The above part is just an analysis of the basic commonality of the use and installation methods of passive infrared detectors. Various brands have their own unique methods in infrared processing. Therefore, we must carefully read the instructions before using and installing. Through the accumulation of practical work experience, we must have a deeper understanding of the characteristics of the detector, so as to better play the role of passive infrared detectors in security engineering.