ADT Fire Detection - Optical Smoke Detection

The Optical Smoke Detector was developed to compliment the Ionisation detector which was the earliest form of smoke alarm. Ion detectors were very limited in their response to smoldering fires, optical smoke detectors responded much more quickly to smoke.

An Optical Smoke Detector uses a light beam to detect smoke in a chamber. When smoke particles scatter a beam of light, a photoelectric cell senses this change in light intensity, causing the detector to go into alarm. Recent developments to the way this light is measured now means black smoke can also be detected, something earlier Optical Detectors were unable to do.

Further developments included the addition, into the ADT MX range, of a High Performance combined Optical and Heat Detector. The heat sensor is used to enhance the overall detection range.

The combined Optical and Heat detector, (High performance Optical detector), responds to smoke in the same way as the Photo Optical detectors, but cleaner/flaming fires create a rapid rate of rise in temperature and produce less smoke. The smoke detectors optical sensitivity is increased so that it can respond to both types of fires, effectively doing the job of both the optical and the Ionisation type detector. HPO detectors can be considered as more universal capable of detecting a wider range of fires.

The latest addition has been the 3oTec, a multi sensor, which includes not just Optical but Heat and CO (Carbon Monoxide), making it the most efficient and effective type of detection available in the world. The addition of the CO detector channel provides further enhancement to the detectors capability to detect real fires whilst reducing false alarms. 

Why Optical Smoke Detection?

Optical smoke detectors are capable of detecting visible smoke produced by materials which smoulder or burn slowly, i.e. soft furnishings, plastic foam etc; or "smoke" produced by overheated but unburnt PVC. They are now also much less sensitive to false alarms than earlier types of detectors. False alarms are one of the biggest hidden costs to industry.  In 2002 the Home Office reported that there were 409,000 false alarms, and nearly half of these were due to equipment failure or misuse. The choice of detection is paramount, as using the wrong detector will result in a false alarm, or worse, it may fail to operate in a real fire!

Features and benefits of MX Optical Smoke alarms include

• Wide range of applications
• High resilience to dust and dirt leading to reduced service costs
• Unique smoke chamber design – Increased response to slow moving smoke
• Low profile, descret and unobtrusive
• Environmentally friendly
• Compatible with all existing MX detection systems
• EN54 Part 7 approved