Smoke Detectors

There are principally 3 types of smoke detection devices
1.Ionisation Smoke Detectors
2.Photoelectric Smoke Detectors
3.Infra Red Smoke Detectors
All of which are available in either conventional or addressable formats.

Ionisation Smoke Detectors

Ionisation Smoke Detectors are generally better at detecting smaller smoke particles such as that produced by rapidly burning fires but are less sensitive to the larger smoke particles generated by smoldering fires etc.

Photoelectric (Optical) Smoke Detectors

Photoelectric Smoke Detectors are generally more sensitive to larger smoke particles such as that generated by dense smoke or smoldering fires but are less sensitive to small particles of smoke found in rapidly burning fires.

The growing use of flame retardant materials in modern building construction has led to Photoelectric (Optical) Smoke Detectors being more widely used and are now the most common detector found in new fire alarms.

Infra Red Smoke Beams

Distances of up to100 meters can be covered by Infra Red Smoke Beams and with control and indicating equipment mounted at low level IR Smoke Beams are ideal for high level detection and / or for covering large open areas such as warehouses, industrial plants and shopping centers etc. where access for installation and maintenance of traditional 'point' detectors would prove difficult.

Heat Detectors

Heat Detectors generally fall in to two categories - Fixed Temperature Heat Detectors and more commonly, Rate of Rise Heat Detectors.

Fixed Temperature Heat Detectors

A Fixed Temperature Heat Detector utilizes a temperature sensing element which will generate an alarm condition if the temperature within the protected area reaches a pre-determined level e.g. 60șC or 90șC.

These detectors are used where high ambient temperatures exist or where sudden changes in temperature can occur e.g. kitchens, boiler rooms & foundries etc. A fixed temperature trigger point should be selected which is most suitable for the situation in question.

Rate of Rise Heat Detectors

A Rate of Rise Heat Detector will include a fixed temperature element as above but will in addition include a temperature sensing element which can detect a sudden change in temperature.This type of detector is more sensitive than a simple fixed temperature heat detector and as such is the choice for applications in which reliable performance and early warning are critical but where the environment makes smoke detection unsuitable.

Multi Detectors

Multi Detectors, combines a Smoke Alarm and a Heat Alarm in a single unit, marks a serious step forward in home fire safety. Previously, Multi-Sensor Alarms were only available to use on big panel-based systems like you?d expect to find in hotels or commercial offices. Now, they?re available for use in home environments too.The Multi-Sensor, as we?ve said, incorporates two alarm types into a single unit; it features both an Optical Smoke Alarm and a Heat Alarm. It?s important to understand that not all fires are the same. Some, for example start off slow and smouldering and produce more smoke and relatively little flame at first; this would be picked up by a Smoke Alarm but not so easily by a Heat Alarm. On the other hand, fast flaming fires with a corresponding fast rise in temperature would very probably set off a Heat Alarm before a Smoke Alarm. By combining the two, a Multi-Sensor offers the best ? and crucially the fastest - possible warning if there is a fire.