Wireless alarms are the backbone of security systems in the private sector today. They are beneficial both in their communication capabilities and simplified technical organization. In particular, the GSM motion sensor forms the basis of this type of household kits. It allows you to timely record the presence of an unauthorized person in the serviced area, promptly sending alarm information to the target address.
What is a motion sensor?
As standard, this is a small device with electronic filling in a compact housing. The device can perform both the function of a detector as part of an alarm system, and act as an independent means of detecting the presence of foreign objects. In the second case, the device has a wider functionality and its own communication system. As for the functionality, the GSM-alarm system with a motion sensor usually provides for the possibilityinstant messaging through a mobile operator, including using MMS/SMS services.
Wired infrastructure can also be used for power supply, but this solution is becoming rarer, since the emphasis is on maximum secrecy and autonomy. Therefore, the batteries are used as batteries or accumulator. The same applies to means of communication, which is provided either by a GSM module or by radio channels operating at a short distance within a private household.
The principle of operation of the device
The main task of the sensor is to perform the function of a physical activity sensor. In this case, it consists in determining the factor of presence in the served area. The principle of operation of the sensitive element depends on the type of device, but in each case, an instant notification is assumed via one of the communication channels that are pre-configured. So, an autonomous GSM motion sensor registers the presence factor without any wires, which it immediately notifies the owner, for example, via SMS and simultaneously sends a signal to the security point (if such a possibility is provided). Also, depending on the selected operation configuration and configuration, the sensor can automatically activate the local siren function - this will also be a reaction to the recorded fact of detecting an unauthorized person in the house.
Types of device
By far the most popularuse the following types of motion sensors with an integrated GSM module:
- Infrared. The principle of operation of this sensitive element is based on fixing changes in the thermal field. This is how pyroelectric sensors work, provided with Fresnel lenses or active detectors.
- Ultrasonic. In this design, the GSM motion sensor responds to acoustic radio waves reflected from moving objects in the control zone. The device itself can generate ultrasonic vibrations, as well as record the slightest changes in a given ultrasonic spectrum. It is important to note that such devices are often sensitive to external factors of changes in the thermal environment. That is, they incorrectly perceive signals near the operating climate equipment.
- Microwave. The operation of devices with microwave sensitive elements is based on the Doppler effect. The sensor operates on the principle of generating radio waves, from which the interference created by moving objects is reflected. A special sensor detects wave vibrations, sending alarm signals at certain frequencies.
- Combined. Each of the above sensors is good in its own way, but also has its own unique disadvantages. Combined GSM motion sensors, in turn, combine the best functional properties of the main detectors, increasing the accuracy of the alarm. The disadvantages of such devices include large dimensions and high cost.
Key Featuresappliance
It is recommended to evaluate the working qualities of sensors and the possibility of their detection by the following parameters:
- Area of action. The coverage radius determines at what distance the device can, in principle, detect movements. Home models, for example, operate in the range of 5-7 m, and the GSM outdoor motion sensor covers up to 15-20 m.
- GSM network parameters. The standard set of frequencies is 900/1800/1900 MHz.
- Viewing angle. It also defines the coverage area, but already vertically. In the simplest models, the sensor angle ranges from 90 to 110°, but more and more often you can find rotational modifications with a detection zone of 360°.
- Food. Again, stand-alone devices are powered by batteries that hold a charge from several days to a week. But there are also network sensors that operate from a single-phase 220 V socket.
- Temperature in the operating environment. Depends on the purpose of the device - for street or home installation. Universal models can be used from -25 to 65°.
What else to consider when choosing a device?
The presence of additional functionality is extremely important for modern signaling systems. On the market, you can find complex devices that also provide temperature, smoke and gas leak sensors. Such a set of sensors will allow counting on the prevention of threats not only of a criminal, but also of a domestic nature. Manufacturers also include cameras with GSM motion sensors in security kits, materialswhich are sent in messages, allowing visual observation at times of alarm. Particular attention is paid to the possibilities of remote notification. The number of telephone numbers to which the sensor can automatically send messages should be foreseen in advance. If you plan to install the sensor outdoors, then the high protection class of the housing must be taken into account. It can be evaluated by a special IP marking with indexes not lower than 54. This designation indicates the protection of the device from rain, dirt and mechanical stress.
Popular device models
The range in this niche is very extensive, but experts include the following among the most successful and balanced in terms of characteristics of security motion sensors:
- Signal XQ 3. Compact machine with automatic setup, microphone and temperature sensor. The best option if you need to service a small area with a high degree of information content at modest energy costs.
- “Guardian of MMS IT”. A fairly simple version of a wired motion sensor for GSM, the limited communication of which is compensated by wide functionality. So, the model supports e-mail, voice communication, sends high-resolution photographs and MMS.
- PIR MP Alert A9. A stand-alone outdoor GSM model that allows tracking with high-sensitivity microphone recording.
- Photo Express GSM. Auxiliary optional tool for complexwireless alarms. The device works on infrared sensitive elements, has a built-in camera and supports the ability to send messages to 6 mobile phones at the same time.
Installation of motion sensors GSM
Motion sensors for the security system are recommended to be mounted in a hidden place. The best option is on the ceiling near the door or window opening. Direct installation is carried out using a bracket, self-tapping screws or dowels. That is, drilling of a wall or ceiling may be required. Also, do not forget that almost all motion sensors with a GSM module are sensitive to thermal equipment, nearby radio and electrical equipment. Some models have a special insulating shell, but it also increases the dimensions of the device.
Feedback on the use of the device
By modern standards, this device has practically no analogues in terms of the principle of detecting an unauthorized person in the room. In this regard, many users point to the efficiency of the device, although not without criticism. Negative impressions from the operation of GSM motion sensors are due to the high rate of false positives. Highly sensitive models react to animals, wind, random radio interference, sounds and vibrations if not properly adjusted. As for GSM communication channels, despite the advantages of alternative radio frequency and network modules for wireless data transmission, cellular communication in this case remainsthe most requested notification method.
Conclusion
The use of alarms with sets of high-tech sensors has long gone beyond commercial and highly professional areas. Today, such equipment can be found in equipping city apartments and especially country houses. In optimized versions, the GSM wireless motion sensor is actively used to service garages, summer cottages and household facilities. The management process practically does not require special attention from the owner and is limited only to periodic revision with maintenance. At the same time, full control over the served area is maintained with a wide range of additional means of automatic notification.
