In essence, the detector is an element of Fire Detection Systems, receiving and processing information about the parameter controlled by it (smoke, heat, light emission). Acceptance of input data for a parameter is by sensing element (sensor), which in turn converts the values of the parameter into an electrical signal. The resulting signal is amplified and adjusted by an amplifier located in the detector and is fed to the threshold element.
An important feature of the detector is its sensitivity. It shows what is the minimum value of controlled parameter, which will cause activation of the detector.
Another important feature of the detector is the area (m ²) guarded by it. This is the area which the detector protects at a height of installation, and in case of fire in a section of that area detector should detect it for a predetermined period of time.
Types of detectors
There are different criteria, which makes classification of the detectors, the most important among which are:
According to the controlled parameter:
According to the configuration:
The most widely used are point detectors that control a Bug Sweeper parameter, close to a point (sensor). Multi-point detectors monitor parameters in close proximity to several or many fixed points (aspiration systems). Linear detectors detect fires along a continuous line (ray detectors, thermo-sensitive cable).
Point detectors – link point
Linear detectors – link linear
Aspiration detectors – link aspiration
For specific application:
For use on vessels
For use in potentially explosive atmospheres
According to the method of measuring the controlled parameter
maximum and differential. The maximum detectors bedded in excess of the value of the parameter of a predetermined value (threshold bedding). Parameter can be smoke, temperature, etc.. Differential (rate of rise) detectors, respond to the rate of change of the controlled parameter, ie if within a specified period of time the temperature changes more quickly than has previously been determined. Temperature differential (ie Termo-differential) detectors have a standard set threshold level of bedding. The last combine two principles in measuring the parameter controlled by one sensor.
According to dispatches to the type of alert control panel
two states detectors, detectors with several states and analog detectors. The first type are typical for conventional systems, and the third – for addressable . Detectors with several conditions can be conventional as well as addressable. In the analog type, electrical signal is most commonly converted and sent in digital form.