The Advantages of and Suitable Applications for OSID


Some environments present unique challenges when it comes to reliable fire detection; high airflows, reflections, vibrations, building movement, steam, fog, dust and other obstructions all make reliable detection difficult.

Xtralis OSID detectors are uniquely designed to overcome such barriers enabling early and reliable response to the presence of smoke. OSID detectors use dual wave-length beam technology, infrared and UV, to determine if smoke is present before raising an alarm.

This type of detection is becoming increasingly common for large open spaces such as indoor sports & fitness facilities and leisure and cultural centres. In these types of buildings, vast internal areas can be as large as 10,000 square metres which often include a mezzanine floor or gallery level which could become passages for the rapid spread of fire or flashover.

Open Space Trend

Large buildings with large open spaces are used all over the world for leisure centres, shopping centres, cinemas, museums, hotels and more. The leisure industry, in particular, is fast-growing with new buildings being built and old ones being refurbished all of the time. With this growth comes an increased demand for fire detection solutions for large open spaces.

Highbury Leisure Centre Fire

In September 2018, a fire ripped through Highbury Leisure Centre causing extensive damage. The fire was caused by contractors working on the roof causing the evacuation of over 100 leisure centre visitors.

Fortunately, there were no serious injuries reported following the fire. However, the fire completely destroyed the centre’s roof leaving the centre out of action for more than eight weeks.

Twelve fire engines and over eighty firefighters attended the scene to bring the fire under control and make the building safe.

This is just one fire that took hold of a large public building, fires like this occur every day and, unless they are detected quickly, can have devastating consequences.

The Solution

The answer to detecting fires in large open spaces is beam detection, in particular, Xtralis OSID. OSID detectors are able to detect smoke that is scattered over large areas which makes them well suited to this type of application.

OSID detection uses two key components; an emitter that emits two wavelengths of light, UV and infrared, and an imager. When the light between the emitter and imager is scattered by smoke particles, reducing the received signal strength by a predetermined amount, a fire condition is generated. OSID supports up to 7 emitters for each imager making it easy to deploy in uniquely shaped areas and emitters can be placed at different heights to overcome stratification and provide earlier detection.

By using two wavelengths of light to detect particles, the system is able to distinguish between particle sizes; the shorter UV wavelength interacts strongly with both small and large particles, while the longer IR wavelength is affected mostly by large particles. Dual-wavelength path loss measurements then enable the detector to distinguish between smoke, dust and other solid intruding particles, thus reducing false alarms.

UK Legislation

If you own, manage or operate a business you are required to comply with fire safety law. When installing fire detection in large open spaces there are two key areas to consider:

Height Limits

The British Standard for fire detection and alarm systems (BS 5839: Part 1) specifies the general height limit for point type smoke detectors as 10.5 metres. However, the specified height limit for photoelectric beam detectors is 25 metres. Therefore, in large open spaces with high ceilings, beam detection is clearly the logical choice.

Product Approval

With the increase of mobile networks and other electronic equipment and the hazards related to Radio Frequency (RF) interference, tighter demands are put on system designers to ensure the products they specify are immune to such phenomenon. Choosing products that are tested by approved bodies such as the VdS shows that the product not only complies with the relevant Electromagnetic Compatibility (EMC) standard but also that the performance of the product meets the requirements of all other relevant standards.

Xtralis OSID is fully approved by VdS for safe use in any European Union country and bears the CE mark to show that it complies with all applicable directives including;  the CPR, EMC and the Low Voltage Directive (LVD).

For more information about Xtralis OSID, or to discuss any of the other products that Eurofyre has available, please feel free to get in touch either by phone on +44 (0) 1329 835 024, by email to [email protected] or via the online enquiry form situated on our contact page.

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