What is BS EN 50402 - Functional safety of gas detection systems about ?
BS EN 50402 is a European Standard that discusses electrical apparatus for the detection and measurement of combustible or toxic gases or vapours or of oxygen.
BS EN 50402 is applicable to detection and measurement apparatus and systems for flammable or toxic gases or vapours or oxygen. It covers apparatus intended to measure reliably, gas concentration and to provide an output signal (alarm and/or measurement signal), the purpose of which is to give a warning of a potential hazard.
BS EN 50402 is dedicated to manufacturers and is applicable to gas detection systems or parts of them (e.g. gas detection transmitters or gas detection control units) as basis for functional safety testing.
Information important for the safe use of the device (gas detection system) will be specified in the instruction manual.
Note: Applications requiring a SIL capability of 4 for a gas detection system are not practicable.
Who is BS EN 50402 - Functional safety of gas detection systems for ?
BS EN 50402 on the functional safety of gas detection systems is relevant to:
- Manufacturers of electrical apparatus used for gas detection
- Manufacturers and suppliers of gas detection devices
- Manufacturers of safety and hazard protection equipment
- Product designers
- Fire safety department
- Local authorities
Why should you use BS EN 50402 - Functional safety of gas detection systems ?
Gas detection systems will fail to function if dangerous failures occur in the equipment used. BS EN 50402 specifies requirements for the functional safety of gas detection systems. It encompasses criteria for reliability, avoidance of faults and fault tolerance. Functional safety is that part of the overall safety that relates specifically to the measures required within the gas detection system to avoid or to handle failures in such a manner that the safety function is ensured. This includes not only design and the development process requirements of the gas detection system but also the information requirements for planning, putting into operation, maintenance and repair.
BS EN 50402 can enable the functional safety characteristics of the gas detection system to be determined from the characteristics of its modules and components. This will enable a gas detection system to be used as a part of an overall safety system.
BS EN 50402 is applicable for gas detection systems, which may consist of the following functional units:
- Gas-sampling
- Sensor
- Signal transmission
- Input to control unit
- Signal processing in a control unit
- Output from the control unit
If you are a manufacturer of gas detection devices and electrical apparatus, compliance with BS EN 50402 can ensure the products meets the required level of operational efficiency, and contributes to the accurate measurements and detection capabilities of gas detection systems.
What’s changed since the last update?
BS EN 50402:2017 supersedes BS EN 50402:2005+A1:2008 which is withdrawn. The following significant technical changes with respect to EN 50402:2005:
- The latest revisions of the metrological standards have been considered
- SIL 4 has been deleted as being not appropriate to gas detection
- Clauses 4 and 5 have been updated for more detailed specification
- Clause 6 for software is new