Fire detection and alarms

Smoke Alarms and Heat Detectors

Smoke Detectors
Smoke Detectors or sensors, are sensitive to smoke in the surrounding atmosphere. Photoelectric/optical smoke sensors use a Light Emitting Diode (LED) and a photodiode sensing element. Smoke particles entering the chamber cause the LED light to scatter, thus triggering an alarm status.  Ionisation smoke detectors use an ionisation chamber. Smoke particles entering the chamber attach themselves to the ions, impeding the generated current flow and causing the alarm to trigger.

Heat Detectors
Heat detectors detect changes in ambient temperature, and send an alarm state to the CIE. Rate of rise detectors, which measure the speed with which the air temperature rises, and fixed temperature detectors, which react when a set temperature is reached.

Multi-Criteria Detectors
These detectors are a combination of smoke and heat sensors, and can be addressable or conventional, the difference being their level of communication to the main fire control panel.

Smoke alarms for the deaf and hard of hearing
Smoke indicators for the deaf and hearing impaired take one of two forms; visual, with the use of a beacon; or tactile, in the form of a vibrating pad placed under a pillow. Installation of a visual smoke alarm in sleeping accommodation satisfies Part M of the Building Regulations. The certification is available for the Smoke/Heat or CO detectors, and/or the individual component parts which make up the kit.

As the only quality mark in this field, gaining the Kitemark will give manufacturers product differentiation and enhanced market reputation. The Kitemark is highly regarded and specified by many local authorities, and will help give manufacturers the competitive advantage with those designing and refurbishing local authority care homes.

BSI's extensive testing facilities
With its impressive Smoke & Heat Tunnel capabilities, BSI can offer full compliance testing for CE and Kitemark schemes against the required standards for smoke and heat detectors.  For multi-criteria detectors, combined testing can be undertaken. This can be complemented with full compliance testing under LVD and ATEX Directives. Kitemark certification schemes for these products will automatically qualify against CE marking compliance.

Smoke Detectors - BS EN 54-7: 2001
Fire detection and fire alarm systems. Smoke detectors. Point detectors using scattered light, transmitted light or ionisation

Heat Detectors - BS EN 54-5: 2001
Fire detection and fire alarm systems.  Heat detectors. Point detectors

Smoke & Heat Tunnel Capabilities

  • Heat generation up to a class C heat detector
  • Software controlled filter paper and aerosol smoke generation
  • Automated alarm registering
  • Three-phase for heat generation and single phase for smoke generation
  • Tests two detectors at any one time
  • Data logging throughout the test cycle for repeatability
  • Optical and Ionisation alarms
  • Temperature tests from 0ºC to 55ºC for elevated and depressed temperature cycles

Sounders or fire alarm devices
Sounders or fire alarm devices are the fire detection and alarm system's means for alerting the occupants of a building to potential or imminent danger from fire.  Sounders vary in size and shape and the sounder output varies in level, frequency range and temporal pattern, but all must comply with the requirements of the same product standard.

There are two types of sounder – outdoor or indoor use. The main difference between the two being the level of protection against the ingress of water or foreign bodies by the use of rubber seals and exterior housing design, and being the severity level of environmental tests applied. The majority of sounders are designed for connection to fire alarm system control panels and are usually rated to operate from a 24V supply. 

There is however variation across different fire alarm systems and fire alarm equipment manufacturers.

BSI's testing capabilities
BSI's reverberation chamber enables testing of sounders to BS EN 54-3, and satisfies product requirements in domestic/commercial markets for size, frequency and sound level.

BS EN 54-3: 2001
The requirements, test methods and performance criteria for fire alarm sounders in a fixed installation – interior and exterior 

Visual Alarm Devices
Until recently, there was no European standard applicable for the construction, robustness and operation of visual alarms. However, now EN 54-23:2010 defines the requirements, test methods and performance of visual alarm devices. There is also a Kitemark certification scheme available for visual alarm devices.

Commercial and public buildings are required to meet the requirements of the Disability Discrimination Act (DDA), which puts the responsibility on the service provider or employer to ensure that reasonable adjustments are made to accommodate disabled people. This includes the use of visual alarm devices in certain circumstances to ensure that hearing impaired people have an equal chance of being alerted to fire risk as other occupants of a building, and may have to be considered as equally important as audible versions – dependent on a number of factors and a risk assessment.

Kitemark certification can be applied to these products, so that manufacturers can prove that their products meet the requirements of the new standard, specifiers and procurement teams can again rely on the integrity of Kitemark to demonstrate quality and fitness for the product's purposes, and end-users can feel that their safety and well-being is assured.

With the need to manage risk and reduce incidents, public and private sector specifiers and procurement teams will be looking for good quality, safe and reliable products. Because Kitemark schemes involve full audits before licence award and continual re-assessment annually to ensure standards are maintained, Kitemark is one of the leading certification schemes available in the UK. As such, if a manufacturer can achieve and hold a Kitemark licence, then CE marking will be a formality when it becomes available from December 2010 and necessary by March 2013 for products sold in the EU under the Construction Products Directive (CPD).

BSI's specialist facilities for testing visual alarm devices at its Hemel Hempstead laboratories can also be used by manufacturers for pre-assessment or developing testing prior to full type approval. These facilities can also be hired by customers to undertake indicative testing for design development in the quest for products, to meet requirements of new standards or regulations.

Voice Alarms
People often tend to react quicker and more appropriately to clear instructions than the sound of bells or sirens. Voice Alarms incorporated into a fire detection system can relay clear and

precise speech messages, helping to minimise uncertainty and confusion in an emergency situation.

With the introduction of the new European standard for voice alarm control and indicating equipment in 2008, manufacturers of products needing to conform to this standard now have the opportunity to enhance their product reputation, and gain market advantage with Kitemark certification.

BS EN 54-16: 2008
Voice alarm control and indicating equipment

Manual Call Points
Despite advanced technology, still the most reliable form of fire detection is human observation. For this reason, fire detection and alarm systems always include the Manual Call Point (MCP), which allows a building occupant to raise the alarm to evacuate the building.

Whether addressable or conventional, the basic principle of operating the MCP is the breaking of a glass element and pressing a button. The Control and Indicating Equipment (CIE) interprets the signal from the button as a fire alarm signal and enters fire alarm mode. Due to the reliability of MCP use, the signal from it includes an interrupt signal, which means the CIE treats it as a priority signal and temporarily suspends all other activities.

BSI's testing capabilities

BSI can offer full compliance testing for CE and Kitemark schemes against the required standards for Manual Call Points. This can be further complemented with full compliance testing under EMC, LVD and ATEX Directives.

Kitemark certification schemes for these products will automatically qualify against CE marking compliance.

BS EN 54-11: 2001
Fire detection and fire alarm systems manual call points.