In case of security and safety products in general, there is one ground rule: Security and Safety products have to be reliable. Starting from this point of view the well-known German certification body VdS (German Damage Prevention GmbH) gets many requests from customers to certify their new products. But a test procedure does not exist for every product.
In this case, VdS researches if there is anything comparable in the field, or how new test procedures can be developed for it. For a product like Bosch’s video-based fire detection software, for example, the tests were out of range of EN-54. Based on this, VdS had to develop a guideline that might also act as a base for an international standard. In general, after going through a lot of thorough testing procedures, a proposal for an independent standard was released. Very often this is much appreciated by engineers in the field as it becomes a state-of-the-art guideline.
The product certification is different in Europe, the Middle East, and in North America. VdS needs to carefully compare the specifications in the various countries and tries to communicate with authorities. The situation at the start was the following: EN-54 did not include any standards governing video-based fire detection. ISO has published a technical specification, but this is not binding and many experts consider it to be incomplete. North America has progressed one stage further: there, video-based fire detection can be certified in accordance with FM3232 and UL268B. But this is of course not accepted within Europe and other countries.
A challenging topic for certification
There is one common understanding: Fire detectors have to be reliable. So, video-based fire detection has to detect smoke and flames at any time, even in dusty environments. It was a big challenge to combine the super-fast detection capability within seconds with a highly reliable alarm. But reliable detection is not the only criteria. It needs to be paired with a very low false alarm rate. If there are too many false alarms, people don’t trust the system anymore. As a consequence, VdS had to ensure that the testing procedures take these considerations into account.
Niche applications, e.g. hangars, logistic centres, high-rise warehouses or sawmills are always linked to a high-risk potential and they are simply expected to work. The manufacturer needs to look for the highest quality in that area. High-end niche applications are not price-driven, but high standards for developing a high-quality product are involved since it is needed to detect fires at an early stage. There are no fines or penalties for a false alarm in fire detection but false alarms need to be limited to the absolute minimum.
Without a certification from a trusted certification body, chances are limited to introduce a product in highly regulated markets like the fire safety industry. This is why manufacturers turn e.g. to VdS as it has the expertise and experience in a lot of countries and is a trusted partner for a lot of authorities. Bosch being also video experts wanted to use its deep knowledge to develop something for the fire industry which is considered to be a very conservative and regulated industry.
No traditional detector can detect smoke and flames at the same time. So for AVIOTEC, VdS has developed a demanding test procedure, incorporating the established VdS 2203 guidelines, “Requirements of fire protection software” and the “Specifications for the testing of flame detectors”, and it has been certified under the reference G217090.
This serves to underline the quality of the product since it has complied with VdS’s stringent testing requirements for safe and speedy detection of test fires. AVIOTEC is therefore the first system worldwide to hold a VdS-certification as an “automatic video camera for visual monitoring of fires, which is used for the purpose of visually verifying fire events”.
Light is faster than smoke
The decisive advantage of video-based fire detection is its speed. It visually detects fires directly at the source, regardless of the smoke migration to the detector. Philipp Mondrik, project manager at the VdS, also underlines its detection speed: “In general, our tests also showed that this video-based fire detection under ideal conditions can be described as ‘earliest fire detection’”.
The algorithm is based on the shape assumed by smoke as it rises and loses density and its characteristic pattern of movement, amongst other information. It detects smoke haze levels as low as 30 percent, whereas most video-based solutions require levels of 50-65 percent. Flame detection uses a physical flame model, based on factors such as flame color, flicker, and shape. The flame characteristics of various fires have been comprehensively analysed to make intelligent video analysis just as reliable as smoke detection.
AVIOTEC meets the important test criterion immunity against false alarms to a special degree. The fire detection algorithms developed on the basis of a physical smoke and flame model, precisely define fire-specific properties and clearly distinguish them from possible disturbance values such as moving objects. It offers new opportunities and solutions for challenging environments where common detectors cannot offer satisfactory reaction times.
For more information, go to www.boschsecuritysystems.com
About the Author
Claus Caspari is a Senior Manager at Bosch Building Technologies - Fire Product Group and is responsible for Standardisation, Regulation and Certification.
