Motion sensors for signaling. Wireless motion detectors

New generations of alarms allow owners to count on a high degree of security function with minimal equipment. Compactness and accuracy of the tasks - the main differences of modern equipment of this type. Such characteristics are achieved in various ways, the most advanced of which involve the use of wireless communication technologies. Also, manufacturers increasingly rely on motion sensors for signaling as an effective means of fixing unwanted objects in the protected area. In a single complex with the control panel, a set of such sensors makes it practically impossible to penetrate an apartment or house without detection.

Motion sensor device

The device is small in size, which allows it to be installed in secluded places. Typically, this type of sensors operate on the basis of infrared radiation, so an appropriate receiver and signal processing circuit are installed in the center. A typical security motion detector is usually provided with a pyroelectric infrared element and a lens that focuses the light, and also registers the incoming signal. It is important to note that the sensitivity of the sensor depends on the number of small lenses used, and the quality of its operation, respectively.

As for the hull, it can be divided into two parts - mobile and fixed. Depending on the modification, the movable side can have several levels of freedom and rotate in different planes. The fixed part allows to reliably mount motion sensors for signaling to different surfaces. Manufacturers in some models of detectors provide special clamping coatings for such sides, which facilitates installation.

Operating principle

Motion sensors are often confused with presence detectors. The difference between them is just the principle of work. If the first device is oriented, rather, to expanding the detection radius, then the presence sensors specialize in processing signals about the visual fixation of the position of the human body. However, in practice, motion sensors for signaling provide approximately similar operation with presence detectors. In both cases, the devices detect the appearance or disappearance of infrared radiation in the observation zone.

It is important to note that the initiator of the signals is not heat, but a change in the characteristics of light on photocells due to human displacement. This is a serious advantage over alternative versions of detectors, since the risk of erroneous operation of the device due to household appliances is minimized. However, today you can find on the market and motion sensors for signaling, the work of which is based on thermal susceptibility. But such devices are more likely to be attributed to the mentioned presence detectors.

Features of wireless models

The main difference between wireless models is the absence of the need for cable connection. This eliminates the unnecessary work in the installation process, saves money, and also enhances the masking of the sensor. Instead of a wired connection, radio modules or network channels are usually used. On the one hand, this principle of interaction with the control panel gives advantages, but on the other - there is a problem of power supply. In the modern range, you can find a motion sensor on batteries that can work for weeks and even months without updating the batteries. For a small apartment this is a good indicator, but if it is planned to provide home alarms with a dozen such devices, then regular replacement of batteries can considerably burden the wallet.

Main characteristics

One of the main performance characteristics is the perceptual angle, which can vary from 180 ° to 360 °. If a security alarm is planned with a motion sensor for a certain entry zone, then the option can be limited to 180 °. With a competent installation and correct calculation of the survey, this angle is enough to fix movements in the doorway. Models with full visibility around the circle are preferable to use for tracking inside the room. Such models are usually installed on the ceiling.

The next indicator of sensor efficiency is sensitivity. The specialists use the formula with the ratio of the active and passive sections to determine the optimal value of this parameter. The intensity of the alternation of such zones determines the level of light susceptibility that wireless sensors of motion intended for installation in a particular room should have.

Types of wireless motion sensors

There are several signs that manufacturers classify such devices. Basically, they are based on the principles of work. For example, there are passive and active models. The first assumes the processing of signals coming from objects located in the observation zone. By this principle, the burglar alarm system operates with a motion sensor that receives infrared radiation. However, there are also devices that analyze the changes in their own signals fed into the environment. These are active sensors, which include ultrasonic devices. They in a constant mode radiate noise waves and at the moment of their deviation from norm fix detection of the unauthorized person.

How to connect a motion sensor?

The device is installed by simple operations with the fastening elements that come with the kit. The main work on the preparation of the device involves connection and configuration. Depending on the method of providing wireless communication, this or that connection scheme is implemented. Usually questions about how to connect a motion sensor are solved by performing two actions. First of all, it is necessary to carry out a kind of activation of the detector. To do this, connect the jumper of the sensor and the main signaling unit for a couple of seconds. The second step involves the installation of appropriate radio frequency between the devices, on which they will interact.

Price issue

In the simplest modifications, such devices can cost about 500-700 rubles. These are compact devices with a small range of action and rather limited sensitivity parameters. In the middle category, you can find a functional motion sensor, the price of which is about 1000 rubles. For this amount, a user can get a quality model not from a Chinese manufacturer, but from a supplier of branded European equipment. It is also not necessary to count on technical and operational refinements, but stability and reliability will be ensured.

The most effective acquisition can be a multifunctional infrared motion sensor. The price of such models often exceeds 2000 rubles, but for this money the device will provide the possibility of working in several modes. For example, in addition to light radiation, such detectors also provide a signal registration based on thermal susceptibility.

Conclusion

With all the efficiency of motion sensors, they do not always guarantee high accuracy when fixing the signal. A big problem in their work is still a considerable percentage of false positives. Nevertheless, in conjunction with detectors of a different type, wireless motion sensors become a fairly effective tool for detecting unauthorized penetration. But it is important not to forget that the accuracy of detection of an attacker does not provide property protection, but only allows the owner to learn about the threat in a timely manner. Therefore, it is important to calculate the further actions of the system after detecting the fact of penetration.