Types of sensors

A sensor is an element of alarm system used for detecting objects, phenomena and physical parameters in the surroundings. Signal from sensor is transmitted to the centre, which records essential parameters, controls the alarm and activates executive elements. Most associated with alarm system are the so-called movement detectors, the function of which is to detect moving around intruder; and the opening detector, known as contactron.

Types of sensors:

PIR – Movement detectors detecting movement by sensing radiation. They are installed mainly at home and in offices

PIR+MW – Movement detectors detecting movement by sensing infrared radiation, and in addition, by using microwaves. It’s a device resistant to sudden temperature changes or air movement. The detectors are installed in rooms with air-conditioning or mechanical ventilation, where doors or windows are draughty etc…

Contactron – Opening detectors, supervising opening of doors or windows. The detector has got a contact, which is closed by magnetic field generated by magnet. If one of the elements is moved away from the other one, then, information is transmitted on to the centre.

Garage contactron – hermetic opening sensor, supervising opening of garage gate. The detector has got a contact, which is closed by magnetic field generated by magnet. If one of the elements is moved away from the other one, then, information is transmitted on to the centre.

Other sensors, which can be frequently encountered in alarm systems are:

Fire detector – detects presence of smoke in a room during initial phase of fire.

Gas detector - its mission is to rapidly detect when threshold value of concentration of one of the gasses is exceeded, and then to inform the alarm centre of such incident.

Leak detector – especially useful when the owners are absent and there is a leak, e.g. due to a broken down pipe in a cellar, boiler room, laundry or kitchen.

Window breaking sensor – reacting to sounds generated when windows are broken; useful at times when someone would want to break in inside through a broken window.