Showing posts with label BS 5839-1:2002. Show all posts
Showing posts with label BS 5839-1:2002. Show all posts

Sunday, February 24, 2019

British and European Standards in Safety & Security

British and European Standards in Safety & Security

When installing any fire safety, CCTV, Access Control, Intrusion items or equipment in a premises it is very important that it meets the highest quality standard and is installed correctly. Also when it is called upon, in a fire situation, it will achieve its function and will operate as expected. Any standard is a collective work. British Standards staff act as secretaries to these committees and project manage the production of standards (BSI is the oldest national standards body in the world).

There can be two British Standards for the same subject for example emergency lighting BS EN 50172:2004 specifies requirements whereas BS 5266-1 is a code of practice giving recommendations. Standards normally relate to products, while the codes of practice relate more to installations, theoretically, codes of practice are not specifications (even though we all tend to use them as such). 


This list of Standards is not comprehensive.
Intruder Alarm Systems
Title or description
DC 04/30080013 (also known as prEN 50131-1 2004)
Intrusion and Hold-up systems. Systems requirements
PD 6662: 2004
Scheme for the application of European Standards for intruder alarm systems
BS 8473: 2006
Code of Practice for the Management of False Alarms
BS 8418: 2003
Installation  and remote monitoring of detector activated CCTV systems
BS 7992: 2002
Code of Practice for exterior deterrent systems
DD 243: 2004
Code of Practice for intruder alarms systems signalling to alarm receiving centres (to be used in conjunction with BS 4737 and BS 5979: 2007 (alarm monitoring)
DD 263: 2007
Intruder alarm and hold-up alarm systems –commissioning, maintenance and remote support
DD CLC/TS 50131 – 7: 2003
Application Guidelines (Intruder Alarms)
BS EN 50131-5-3: 2005
Requirements for interconnections equipment using radio frequency techniques
BS 7042: 1988
High security intruder alarm systems in buildings
CCTV

BS EN 50132-7:1996
CCTV Surveillance systems for use in security applications – Applications Guidelines
BS EN 62676 Series
Video surveillance systems for use in security applications
BS 8418: 2003
Installation  and remote monitoring of detector activated CCTV systems
Access Control

EN 50133-1: 1997
Access Control – Systems Requirements
EN 50133-7: 1999
Access Control Systems for use in security applications – Applications Guidelines
Monitoring Centres

BS 5979: 2007
Code of practice for remote centres for alarm systems
BS 8418: 2003
Installation  and remote monitoring of detector activated CCTV systems
BS 7958
The management and operation of CCTV monitoring
BS 8484: 2008
Lone worker monitoring
Alarm Transmission Systems

BS EN 50136 -1-1: 1998
General Requirements
BS EN 50136 -1-2: 1998
Requirements for using dedicated pathways
BS EN 50136 -1-3: 1998
Requirements for systems with digital communications using the PSTN
BS EN 50136 -1-4: 1998
Requirements for systems with voice communications using the PSTN
Emergency Lighting

BS 5266-1- 2011
Gives general rules and guidance on the provision and operation of emergency lighting in most premises other than dwellings
BS EN 60598-1: 2008
Luminaire’s. General requirements and tests. Check out the 60598 series for particular requirements.
BS EN 62034:2006
Automatic test systems for battery powered emergency escape lighting .Specifies a test system for battery powered emergency lighting
Fire Alarm Systems

BS 5839-1:2017
Fire detection and alarm systems for buildings. Code of practice for the design, installation, commissioning and maintenance.
BS EN 54
Fire detection & alarm systems
BS 5839-6:2004
Fire detection and alarm systems for dwellings. Code of practice for the design, installation, commissioning and maintenance.
Fire Door

BS 8214:2008
Code of practice for fire door assemblies
BS EN 1634-1:2008
Fire resistance and smoke control tests for door, shutter and, openable window assemblies and elements of building hardware. Fire resistance tests for doors, shutters and openable windows which is an alternative for BS 476 – 22: 1987
Portable Fire Extinguishers

BS EN 3-10:2009
Provisions for the attestation of conformity of portable fire extinguishers in accordance with EN 3 Part 1 to Part 5. Amendment 1
BS EN 3-7 2004 + A1: 2007
Characteristics, performance requirements and test methods
BS 7863:2009
Recommendations for colour coding to indicate the extinguishing media contained in portable fire extinguishers
BS 5306-8:2000
Code of practice for Selection and installation of portable fire extinguishers.
BS EN 13565-2:2009
Fixed firefighting systems. Foam systems. Design, construction and maintenance
Security Guarding Services

BS 7499: 2002
Static site guarding and mobile patrol services
BS 7984: 2001
Keyholding and response services. Code of Practice
BS 7960: 2005
Door Supervision and Stewards
BS 7872: 2002
Manned Security Services. Cash in Transit Services. Code of Practice
Miscellaneous Standards

BS EN ISO 9001: 2000
Quality Management Systems: Requirements
BS EN 14001
Environmental management systems:  Requirements
BS OHSAS 18001:2007
Occupational health and safety management systems: Requirements
BS 7858: 2006
Security screening of personnel employed in a security environment
BS 7671: 2008
Requirements for electrical installations. IEE wiring regulations. 17th Edition.

Ref: BS & EN websites. 

Wednesday, September 17, 2014

Service and Maintenance for CCTV

Service and Maintenance for CCTV
1. General:
Effective and regular maintenance of a CCTV surveillance system is essential to ensure that the system remains reliable at all times. It is advisable that maintenance of the CCTV system should be carried out by the company which installed the system. However, the maintenance company should have the means, including necessary spare parts and documentation, to meet the recommendations given here.
Note: This recommendation does not place an obligation upon customers who purchase their systems to have them maintained by the installing company. Maintenance is a matter of agreement between the customer and the installing company or a separate maintenance company. Maintenance comes under BS EN 62676-4 Clause 17 & SC CoP Guiding Principle 10.

The preservation of security within the maintenance company is of paramount importance and steps should be taken to ensure the safe keeping of all customers’ equipment and documentation relating to a particular installation/contract.

Note: BS EN 50132-7 states that “CCTV systems should be maintained in accordance with the schedule supplied by the system designer or supplier”, but does not detail any specific maintenance requirements. These guidelines give specific advice for the maintenance of CCTV surveillance systems, and provide examples of the type of documentation required to be used by the service company.

A maintenance company should ensure that adequate vetting of all employees is carried out. All employees, who visit a customer’s premises, shall carry identification cards which should include a photograph and signature of the bearer, the company’s name, contact details and a date of expiry (maximum of 3 years).
Each service technician employed by the maintenance company should carry a range of tools, test equipment and other equipment to enable them to perform their functions satisfactorily. Specialist tools, test equipment and plant should be available for deeper investigation if necessary.

Note: Disconnections, for whatever reason, should be recorded on a maintenance record and authorised by the client or his representative.
The maintenance company’s organisation should be so staffed as to ensure that the recommendations of this Code of Practice can be met at all times. The following factors should be taken into consideration:

  •       .  the number of installations to be serviced
  •        the complexity of the installations;
  •   . the geographical spread of the installations in relation to the location of the maintenance company, its branches and its service personnel
  •      .   the method of calling out service personnel outside normal office hours, where applicable.
  •     Service personnel should be adequately trained and training should be updated whenever appropriate.
Maintenance Service is 3 types but scope of work is same.
A.   Preventive Maintenance service.
B.   Corrective Maintenance service.
C.   Performance Maintenance service.

A. Preventative Maintenance
I. Frequency of visits
The following recommendations apply, unless the customer has agreed an alternative schedule of works with the maintenance company. It’s also called Planned maintenance.
Preventative Maintenance Inspection
As a minimum, this should include all the elements detailed in Clause II, and the intervals should not exceed 06 months. Customers may agree a more frequent visit where appropriate. During the 1st Visit you should note down all CCTV related Product Make, Model Nos with Version. If required make a hand sketch of geographical span.
Supplementary Preventative Maintenance Inspection
As a minimum, this should include the supplementary items detailed in Clause III. These supplementary inspections may be carried out at the same time as an annual visit or at less frequent intervals, dependent on the agreement between the customer and the maintenance company.

II. Preventative Maintenance Inspection (Scope of work)
During each preventative visit, inspection of the following, with all necessary tests, and those rectifications which are practical at the time, should be carried out:
Control Room:
1. Check the picture quality of each camera and monitor. Look for signs of condensation on housing windows and limiting of picture highlights, i.e. proper focus, proper resolution, Signal strength etc.
2. Check all controllable functions for each station e.g. pan, tilt, zoom, focus, iris, speed, auto-pan, wiper, pre-sets etc.
3. Check camera / monitor combination selection, proper functioning of Live/Spot monitors.
4. Check the operation of recorder (s) i.e. record, backup and replay.
5. Check the operation of special equipment such as video multiplexers, Storage.
6. Check any interfaces with alarms e.g. movement alarms, fences etc.
7. Check that all indications function correctly.
8. Check the IP setting at IP Camera and NVR/DVR.
9. Check BNC/RCA, LAN & Power connector at DVR/NVR/ Control Room.
10. Check the PATA/SATA cable for Hard Disk/RW. RS484 Cable.
11. Check the proper functioning of Mouse, USB port, RS485/232 port, DVR key/ Remote etc.
12. Check proper functioning of CCTV Software/Control Station/ Monitoring Software/Analytic software.

Around the supervised premises
1. Check that camera movement and field of view is free from obstruction, trees etc.
2. Check that ALL warning labels are in place (e.g. movement, voltage, LASER)
3. Check that indicator lamps are working.
4. Request that customer checks the operation of supplementary lights, including IR, at night. Leave a form and request that any faults are reported.

III. Supplementary Preventative Maintenance Inspection
During each Supplementary visit, inspection of the following, with all necessary tests, and those rectifications which are practical at the time, should be carried out:
1. Carry out all functional maintenance checks.
2. Check that external, flexible cables (Video, Power, Fiber, LAN) are properly supported and undamaged.
3. Examine all metalwork especially towers, brackets & box, for signs of corrosion and damage.
4. Lower towers and check cable for fraying. Grease the mechanism.
5. Check all glands and seals on external equipment.
6. Check all external and internal flexible wiring for signs of wear and fraying.
7. Check all fixed and flexible conduit for signs of damage.
8. Remove covers and housings and clean interiors (Lens, Camera Body, Fan, Power/Fiber Board etc) where necessary. Each camera bracket fittings and clamping bolts are tight.
9. Check the function and wear of wiper blades and washers.
10. Check the function of heaters/Cooler, Solar panel (if applicable).
11. Check the function of supplementary lighting, including IR, and photocells.
12. Check the integrity of all supports, Antenna, including cables & BNC/LAN.

Note: It is recommended that all filament lights/lamps should be replaced during this visit.
Those parts of a system, or any environmental conditions found during preventative maintenance, which could reduce the effectiveness of the system should be identified on the maintenance visit record.
Routine maintenance visits to the supervised premises should be made by a representative of the company at intervals of not less than once a year (as per SLA). Should the company, the customer or his insurer, require more frequent maintenance, this should be clearly stated in the maintenance record and in the contract documents.

Note: :If it is necessary to undertake routine maintenance work outside normal working hours, it is recommended that the contract between the customer and the company should state this requirement.

Those items of inspection or rectification which are not carried out at the time of routine inspection should be completed within a period normally not exceeding 20 days, other than by alternative agreement with the customer.
Before leaving your place provide answers to any questions or queries that you may have. Complete maintenance report and discuss work conducted with you. All work carried out on site, together with time of arrival is recorded on a record sheet (known as a docket / Case ID). The engineer will also note down any deficiencies in the system and recommend work required to maintain, full, trouble free operation. This docket is shown to your (customer) copy provided(Service Report/memo/ value reports) for placing on the file. Excludes provision of high reach equipment.

IV. Emergency service/Breakdown Call
Where an agreement exists, the customer should be kept informed of the address and telephone number of the company's service and emergency service facilities (Service call). It is recommended that except where otherwise agreed by the customer, the company’s emergency service facility should be so located and organised that under normal circumstances the company's representative should reach the supervised premises within eight hours from the notification of the fault. This recommendation need not apply to other than mainland installations. Whenever possible, the customer should be informed of any likely delay when a fault is notified.

B. Corrective Maintenance service.
Service remains same as per Preventive Maintenance (Clause I to IV). Its including all spare parts. Rapid repair of equipment that has broken down is critical to ensure uninterrupted operations, minimal downtime and optimal functionality. maintenance company offers Corrective Maintenance services to provide emergency maintenance support in the event of an unexpected breakdown of equipment and for timely resumption of operations. With Corrective Maintenance you can be assured their engineers are available when needed and that you have the backing of Maintenance Company’s extensive knowledge and support network.
Features:
1)      Technical Helpdesk support located at Maintenance Company.
2)      Travel and labour costs are included as well as replacement of parts due to wear and tear. Consumables are excluded.
3)      Maintenance company response Time commitment can be within hours after your first call.
4)      Spare parts to replace faulty components will be available during the whole length of the contract.
Benefits:
1)      Simplicity: just call and within 8Hr Maintenance company engineers will be there..
2)      Low-Risk: by ensuring the availability of your security systems you optimize your daily strategic operations.

C. Performance Maintenance service.
Service remains same as per Preventive Maintenance (Clause I to III). Its including all spare parts & Maintenance company engineers are available when needed. Technician / Engineers deputed on your (Customer) Control Room.
Features:
1)      Technical Helpdesk support at your (Customer) place.
2)      Our Response Time commitment can be within hours after your first call when Maintenance company field technicians are on-site.
3)      You decide when you want on-site technical assistance to be available: eight hours every working day, weekdays and weekend, around-the-clock or according to your own tailored schedule.
4)      Spare parts to replace faulty components will be available during the whole length of the contract.
5)      Online Monitoring gives you real-time information on your system and is crucial for delivering on the Performance Maintenance commitment.
6)      Carry out a visual inspection of all major components for signs of deterioration or damage and rectify as necessary.
Benefits:
1)      Simplicity: Availability of Technicians/Engineer 24hours a day, 365 days a year.
2)      Fast Response: you enjoy preferential treatment and Response Time commitment to rapidly restore the operation of your security systems.
3)      Risk-free: We take full responsibility for managing your security processes
4)      You know how fast your system will be up and running after any incident.
5)      Total peace of mind.

If you can get any Service and Maintenance for CCTV minimum you must maintain below point.
Do not make customer aprilfool.

Visually inspect all major components and connections for signs of deterioration or damage
Check all control equipment (DVRs, VCRs, monitors, multiplexers, video switchers, telemetry units etc) for correct operation
Check mains & power supplies and stand-by batteries including charging rates.
Check environmental conditions for adverse effects, including growth or shrubbery obscuring camera views
Check time and date settings in equipment and update the settings as appropriate
Check integrity of all cabling and sample check external insulation for damage
Clean cable fixings for security
Check auxiliary lighting equipment, infra-red units and photocells (if any) for correct operation
Check air vents are clear in all control equipment including PCs
Clean cameras, lenses and housing surfaces as necessary
Check al glands and seals on external equipment
Clean control equipment surfaces including PC (if applicable)
Establish regular back-ups are taken
Check camera is aligned to user specification, pictures for correct field of view and adjust as necessary
Check brackets, towers and fixings for corrosion or damage. Check clamping bolts/brackets are tightened correctly
Check wash/wipe units and wiper blades (if any) for correct operation and fill washer reservoir where necessary
Check quality of recording during day time and night time modes
Check pan and tilt assembly (if any) including fixings, electrical connections and functions.
Check the satisfactory CCTV transmission of images to remote site (if applicable)
Check warning signs are in place
Check all camera presets
Check all alarm presets

Monday, October 22, 2012

Video Smoke Detection Technology



Video Smoke Detection (VSD) or Video Image Detection (VID) systems have been developed to overcome many of the problems associated with smoke detection. It provides solutions for previously unsolvable fire detection scenarios, working externally as well as internally and represents a true technological breakthrough in fire detection.
VID / VSD CAMERA

 Video Image Smoke Detection (VISD) is based on the computer analysis of video images provided by integrate CCTV cameras into advanced flame and smoke detection systems. VSD automatically identifies the particular motion patterns of smoke and alerts the system operator to its presence in the shortest time possible. This enables a fast response to a potential fire, saving valuable time even in voluminous areas or where a high airflow may be present.

Smoke VID systems require a minimum amount of light for effective detection performance and most will not work in the dark, on that case used IR sensitive cameras. Flame VID systems can operate effectively in dark or lit spaces and some systems will have enhanced sensitivity to flaming fires in the dark.


In applications ranging from turbine halls to historic buildings, road tunnels, rail depots, warehouses, shopping malls, aircraft hangars and many others. Camera-based fire detection system has become established as the leading edge technology in the field of fire protection.

Fire safety professionals constantly seek the benefits of early warning of potential fires. In a perfect world it would be possible to place hundreds of smoke detecting sensors above and around any items or areas at risk. This would certainly enable a fast response to a potential fire, saving valuable time even in voluminous areas or where a high airflow may be present. But of course such a dream is not possible from a practical or financial point of view.

Video smoke detection technology makes this dream a reality.    

How it works -  Video Smoke and Flame Detection


Video smoke (VISD) and flame detection (VIFD) is performed by a software algorithm running on Visual Signal Processors (ViSPs) that implement parallel processing engines in hardware. Video images are analysed in real time by applying digital image processing techniques that allows smoke and flames to be detected with a high degree of confidence. The video image is continually monitored for changes and false alarms are eliminated by compensating for camera noise and acquiring knowledge of the camera view over time.
an illustration of how the Video Smoke Detection process works





Multiple zones can be defined for a camera view in which smoke and flames are to be detected. Each zone has a set of parameters that provide complete control over the detection algorithm. These parameters are configured individually for each zone in order to cater for a wide variety of application scenarios. It is also possible to combine information from multiple cameras to enhance the detection process.



Stemming from many years of research and development several complex statistical and geometrical measurements are made on the video image data from each zone as dictated by the control parameters. This is made possible by the parallel digital signal processing capabilities of the hardware. The scale of parameter settings is such that it is possible to detect smoke ranging from slow emerging faint smoke through to dense smoke plumes that are produced in a short period of time.


Once the measurements have been made from the video image data a set of rules can be applied to determine if they characterise smoke or flames. The rules can also be tuned to meet the specific application requirements to complete a robust and successful detection algorithm.


Video Smoke Detection Principles

VSD/VID (VISD) is based on sophisticated computer analysis of the video image seen by the CCTV camera (sensor). Using advanced image-processing technology and extensive detection algorithms (and known false alarm phenomena); the VID can automatically identify the distinctive characteristics of smoke patterns. The fire detection industry has an abundance of known smoke signatures and these are built into the system to give an accurate decision on whether smoke is present.

The VSD system uses standard CCTV equipment linked to a self contained processing system which is capable of recognising small amounts of smoke within the video image and alerting the system operator both at the processor and by a variety of remote outputs.

The VSD system employs highly complex algorithms to process video information from CCTV cameras simultaneously. The video hardware is designed to allow simultaneous real time digitising of all images, which means that the system does not multiplex images and, therefore, no information is lost or delayed. All alarm condition images are logged, time & date stamped, and stored within the system’s memory.

The VSD system detects smoke rapidly by looking for small areas of change within the image at the digitisation stage and only passing these pixel changes to the main processor for further filtering.

The video information is passed through a series of filters, which seek particular characteristics that can be associated with smoke behavior. Further analysis is then carried out on the relationships between the filtered characteristics to determine whether all the conditions have been met for the system to confidently predict the presence of smoke.

The system installer has the ability to vary the amount of smoke signal, and the length of time that the smoke exists before an alarm condition is raised to cater for situations where there may be background smoke present. The installer may also divide the video image into up to 16 zones and programmed the system to alarm only if smoke is present in multiple zones. Each zone can also be separately configured to generate an alarm at different levels of smoke activity.

The performance of a Smoke or Flame VID system must take into account three general items:
1. Fire sources
2. Environment
3. System variables


What it Overcomes

Standard smoke detection systems, be they point detection systems, infra-red beam detectors or aspirating systems all require the smoke generated from any combustion to reach them before they can recognise the particulates and activate an alarm. Such systems can function very effectively in internal thermally stable environments with low to moderate ceiling heights.

In large volumeous spaces such as enclosed sports arenas, exhibition halls, aircraft hangers and atriums, solar radiation, air conditioning systems and translucent glass all contribute to an increasing ambient temperature from floor to ceiling, known as a thermally stratified environment.

In a smouldering fire or low energy flaming fire scenario the raising combustion products cool as they rise through the air and move further away from the centre of combustion. In a temperature-stratified environment the ambient air temperature increases with height. As the combustion plume rises it cools, if this cooling reaches equilibrium with the temperature of the ambient air the smoke products will loose their buoyancy and move laterally to produce a roughly horizontal layer.  If the temperature slowly increases the hot air above the smoke will expand thus further reducing the height of the smoke stratification layer.

In environments with a high percentage change of air caused by either high velocity air-conditioning (HVAC) systems, or large open doors, smoke particles generated during low energy combustion can become quickly dispersed or diluted to the point where there are insufficient concentrations to activate an alarm in a standard smoke detection system.

These twin problems of stratification and dilution can seriously delay or even prevent a smoke detection system from entering an alarm state.

VSD systems over come both of these phenomena by looking below any stratification or dilution boundary at the incept point of any potential fire and identifying smoke generation at or very close to the source.

So, be separately configured to generate an alarm at different levels of smoke activity.

In general, VSD systems do not have fixed settings. They have many parameters that need to be adjusted to provide the optimum response to a specific fire risk. Therefore, it is very important that the manufacturer should be fully consulted in matters of product application and system design. The manufacturer’s installation, commissioning and service and maintenance instructions should also be followed.

Location and spacing

The location and spacing of detectors shall be based on the principle of operation and an engineering survey of the conditions anticipated in service. The manufacturer’s published instructions shall be consulted for recommended detector uses and locations. an engineering evaluation that includes the following:
(1) Structural features, size, and shape of the rooms and bays
(2) Occupancy and uses of the area
(3) Ceiling height
(4) Ceiling shape, surface, and obstructions
(5) Ventilation
(6) Ambient environment
(7) Burning characteristics of the combustible materials present
(8) Configuration of the contents in the area to be protected

Codes and Standards

The National Fire Alarm Code, NFPA 72-2007, recognizes the use of flame and smoke VID systems. (5.7.6 Video Image Smoke Detection; 5.8.5 Video Image Flame Detection) Per the Code, the installation of these systems requires a performance-based design. There are no prescriptive sitting requirements. Flame VID systems are classified as radiant energy sensing fire detectors and are treated similar to optical flame detectors. Due to the variability of VISD system capabilities and the differences in alarm algorithm technologies, NFPA 72 requires that the systems be inspected, tested, and maintained in accordance with the manufacturer’s published instructions.

Currently, there are no systems that are UL listed, and there is no UL standard that specifically addresses VID/VSD systems. Four systems have been FM approved. These include a system that detects only smoke, one that detects only flame and two that detect both. The systems have been approved to meet the requirements of FM Standard 3260, Radiant Energy- Sensing Fire Detectors for Automatic Fire Alarm Signaling, and UL 268, Smoke Detectors for Fire Alarm Signaling Systems.

The effect of all the changeable parameters in the VSD, such as camera lenses, software parameters adjustment and lighting conditions should be taken into consideration following the consultation principle given in BS5839 Part 1: 2002, clause 6.

BS 5839-1:2002 recognises the existence of VSD. Clause 21 j) recommends that:
"Video smoke detection systems should be capable of detecting smoke reliably in the absence of the normal lighting in the building and the absence of the mains power supply to any lighting provided specifically to aid the detection of smoke."

Environmental & Hazard Parameters

The foundational information collected for identifying typical/standard fire and smoke scenarios, likely false/nuisance scenarios, and a range of ambient conditions to which VISD systems may be subjected in the three target applications. This work included researching and reviewing fire incident data and conducting an industry workshop on VISD technology. On-site surveys and interviews with end-users were also conducted.

Installation of VSDs

Installation cables should be in accordance with the recommendations of BS 5839-1:2002.

Advantage of VISD Early fire detection

A VSD detecting fires in certain large open areas and areas of special high risk as:
1. VSD systems can be used for outdoor applications, such as train stations and off-shore oil platforms.
2. The ability of VSD to be programmed to provide different sensitivity (range) by lens selection, and to adapt to difficult application environments (false alarm sources) by tuning software operational parameters, makes it an ideal detection tool in special applications where an engineered solution is likely to give the best answer.
3. The ability to protect a large area, and/or areas with excessive ceiling heights, while still achieving fast detection. With VSD, smoke in the camera field of view can be detected whereas with other detector types, smoke has to migrate to, and be present in, the sensing area e.g. the sensing beam of a beam detector or the sensing chamber of a point smoke detector.
4. VSD, by providing accurate location of the incident, will benefit applications where targeted fire protection measures are required.
5. The ability to have live video immediately available upon detecting a pre-alarm or an alarm condition. This immediate situational awareness allows monitoring personnel to easily view the protected area to determine the extent of the fire and to more accurately identify the location.
6. Archiving of still and video images associated with alarm conditions also provides a means of assessing the cause of incidents and provides a basis for changes in the detection system if the event was a false/nuisance alarm.
7. The ability to sub-divide the image into different areas for separately identifying fire risks or programming out (masking) known sources of potential false alarms.
8. VSD, by providing visual verification of the event, will give operators information to facilitate a better and faster structured response of an incident and enable safer investigation by remote viewing.

Testing, servicing, maintenance and replacement

It is important to always follow the manufacturer’s recommendations for testing, servicing, maintenance and replacement requirements. It may be desirable that, in some installations where the effect of potential false alarm sources cannot be fully determined, a period of trial is undertaken before completing the commissioning of the system and handing it over to the client.

A method, appropriate to the risk, of testing the effectiveness of the VSD at both the commissioning stage and at subsequent service and maintenance visits should be agreed with the equipment manufacturers or system installer. Tests should be conducted and documented in accordance with this method.

VSD should NOT be used in the following situations

1. Where certain processes are likely to produce smoke-like images which may be misunderstood by the video analysis software, unless it has been demonstrated through trial and, if required, tuning of the equipment so that the effect of these false alarm sources have been adequately established and eradicated. Examples include processes generating large amounts of steam and/or other gas plumes (exhaust fumes from forklift trucks) and/or environmental pollutants (vapour, dust, sprays). In outdoor or semi-outdoor situations this may also include insect swarms.
2. Where a deterministic response to known fires is required and can be achieved by the use of EN 54 approved detectors, i.e. most standard commercial and industrial applications.
3. Where there is a danger that the ambient lighting level is either too low or too high to obtain a satisfactory response from the VSD at the time it is required to monitor the risk, unless specific provisions are available to alleviate this danger. For example infrared illumination of the scene with back-up power supply, polarized lens filters, or where very intense light sources can blind the camera.
4. Where there are significant obstructions in the camera line-of-sight of the main identified risk or where such obstructions are temporary and of an unpredictable nature.
5. Where a particular equipment configuration, including installation cables, would not assure the integrity of the alarm transmission path through the system so as to provide the desired warnings to the occupants of a building or the desired response from the emergency services.
6. Where likely environmental conditions present may have an adverse effect on the ability of the VSD to properly operate. For example this would include fog, mist, snow and rain.
7.  Where the use of cameras is not appropriate due to data protection issues.