Motion detectors for burglar alarms - volumetric and infrared

Security sensors, they are also motion sensors for signaling, are modern equipment that allows you to accurately find intruders on a private territory within a covered radius of action. The principle of operation of such devices may be different, due to different types and technical characteristics.

Why is a security motion sensor needed and where is it used?

The main task of such a device is to calculate movement in a protected object or territory, for example, in a car or on a personal plot. Fixing extraneous movements, the controller transmits a signal to the control panel, warning the owner of potential danger. If the sensor is additionally equipped with a video camera, it will also record everything that happens around.

The purpose of these types of equipment may be different, it all depends on their design features and functionality:

• Controllers can be installed to activate lighting systems when people enter the room. These technologies save energy and extend the life of electrical appliances.
• Home sensors. They are mounted to identify unauthorized persons in the protected area. The devices transmit signals about the presence of extraneous movements to the security panel.
• To transmit alarm signals to mobile devices, tablets and users' computers. This option is available to people whose equipment is equipped with a GSM module, and also has the ability to connect a SIM card.
• They can be used as an additional working unit for connecting light and sound devices.
  
• For the operation of control systems of protected premises, as well as for optimal operation of video cameras.
• For installation in cars as car alarms. You can mount and connect to anti-theft machine systems. Such systems promptly transmit to the car owner information that someone has entered his car.

Infrared security GSM-sensors equipped with a siren and a camera are used to guard any objects.

Types of sensors and principle of operation

The principle of operation may differ slightly depending on the type of sensor.

Infrared motion detectors for security

This type of security sensors is considered the most advanced and demanded. The principle of operation is based on capturing thermal radiation and determining optical reflection. The device, like any other infrared radiator, is capable of emitting a large amount of heat waves.

Ultrasonic and radio wave sensors

The operation of such devices is based on the principle of capturing and reflecting sound streams. Today, these types of devices are practically not used anymore. After connecting and tuning, the controller picks up sound waves in the frequency range of 20 - 60 kHz. As a return pulse, the light radiation is fixed with the help of built-in lenses.

Photoelectric sensor

The principle of operation is almost identical to the previous one, the main difference is that the controller produces an electromagnetic field.Movement detection occurs by detecting reflection pulses. Electromagnetic controllers operate at approximately 5.8 GHz.

Types of outdoor sensors and requirements for them

When choosing motion sensors for protecting a backyard or other perimeter, it is important to take into account the following requirements:

• The number of false positives should be kept to an absolute minimum.
• Stability of the structure to external factors.
• The sensor must ensure the effective operation of the entire security system, regardless of weather conditions and temperature conditions.

When guarding the perimeter, it is important to take into account the design features of the entire area. To cover all areas, it is recommended to equip the area with different types of motion detectors:

• Microwave motion detectors. The operation of the device is based on the Doppler effect. The built-in generator emits high-frequency waves. The working nodes continuously analyze this parameter and, when changes, are triggered. The advantages of this type of device allow you to cover large areas, the disadvantages - due to the high power consumption, there are no wireless modifications.

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  Acoustic, they are also ultrasonic, motion sensors. The work is based on the principle of sound location. The built-in generator emits powerful sound vibrations that the human ear cannot pick up. Sound beams bounce off objects, resulting in a change in frequency. The device detects the difference - a signal is sent to the control panel.

• Thermal sensors are produced on the basis of a PIR sensor, which is capable of capturing infrared radiation in the protected area. Infrared rays emanate from each living organism, which the device captures, focuses using optical Fresnel lenses and transmits a signal to the control panel. The maximum allowable working angle reaches 120 degrees, and the recognition range of a living object ranges from 10-15 meters.

Each type of equipment has not only advantages but also disadvantages. To choose the right device, you need to carefully read the characteristics, features and reviews.

Features of installation and connection

Before proceeding with the connection and configuration of the equipment, it is important to connect it correctly. Security sensors are installed on special structures that are not subject to vibrations. Compliance with this rule is mandatory, otherwise the number of false positives will increase significantly, which will negatively affect the quality of work. In addition, the height of the device plays a role. The critical height indicator is indicated in the technical passport of the device and, as a rule, fluctuates within 2-3 meters from the floor level.

When installing all the considered types of security sensors, their disadvantages should be taken into account. For example, for efficient and correct operation of infrared devices, you need to place them as follows:

• In the immediate vicinity, there should be no heating and any heating devices that form ascending heat fluxes.
• Avoid direct sunlight on the sensitive segment of the device - pyromodule.

The detection zones of the detectors are necessarily controlled by the possible paths of the intruder's movement.

Configuring Sensors

For wireless models, the classic concept of connection is absent. The sensor is assigned a unique combination of numbers and letters for the alarm system; when it is turned on for the first time, it automatically switches to operating mode without additional settings. The connection diagram and settings are presented in more detail in the attached technical data sheet for the device. Each model has its own subtleties.

Wired professional devices are connected in different ways, depending on whether this model is addressable or not. The addressable detector must be connected with the obligatory observance of the polarities. Most models of security sensors are equipped with a relay, the contacts of which open in the danger mode, and closed in the monitoring state.

The tamper is used to prevent the device from being opened by third parties. If you do everything thoroughly, it is better to connect it to a specially designated loop in the network.

Criterias of choice

Before purchasing equipment, you need to carefully consider all the details that will make the use of the sensor more comfortable, convenient and productive. If the wrong device is selected, due to technical limitations, it can create many difficulties in use and maintenance. The main selection criteria that you should pay attention to:

• The purpose of the device is a key factor. You should also decide on the place of operation of the device - indoors, inside a car, etc., or on a personal plot. The presence of visors, awnings also plays a role, since it depends on what IP protection class the selected device model should have.
• Sensors are divided into several types according to the mounting methods - they are mounted and built-in.
• The power of the device is determined by the range of the security sensor and the ability to record events occurring around it (sensitivity). Also, installation rules and dimensions depend on this parameter.
• When choosing a type of device, the design feature of the house, as well as the terrain conditions, is of great importance. For example, not every modification of the model is capable of shining through glass surfaces or light structures such as awnings and arbors.
• It will not be superfluous to familiarize yourself with the response times. This is of great importance, especially if the security sensor is installed indoors.
• The installation location determines the detection angle of a moving object.

Sensor models equipped with sensing elements reduce the concentration of false inclusions of the device, and also allow you to select the appropriate operating mode.