ISO 7240-6:2011

Overview

ISO 7240-6:2011 - "Fire detection and alarm systems - Part 6: Carbon monoxide fire detectors using electro‑chemical cells" specifies requirements, test methods and performance criteria for point-type fire detectors that use electro‑chemical sensors to detect carbon monoxide (CO) in building fire detection and alarm systems. The standard covers design, marking, functional indicators, on-site and manufacturer adjustments, monitoring of detachable detectors, and a comprehensive suite of environmental and performance tests.

Key technical topics and requirements

• Scope and applicability: Applies to point CO fire detectors based on electro‑chemical cells. Other CO detector technologies may use this document for guidance only. Special-purpose detectors developed for specific risks are excluded.
• Performance and test methods: Defines test procedures and acceptance criteria for detector response, repeatability, reproducibility, directional dependence, long‑term stability, saturation and fire sensitivity.
• Environmental and mechanical tests: Incorporates environmental testing (cold, dry heat, damp heat, vibration, shock, impact, corrosion) referenced to IEC 60068 series standards.
• Electromagnetic compatibility (EMC): Immunity requirements are aligned with EN 50130‑4.
• Functional requirements:
  • Individual alarm indication - each detector must provide an integral red visual indicator visible from 6 m at up to 500 lx illumination (with specified viewing angles).
  • Monitoring of detachable detectors - removal of detector heads must be detectable by the control system.
  • Manufacturer’s and on‑site adjustments - settings must be protected (special code/tool or seal); on‑site adjustments allowed only under controlled conditions and must maintain compliance.
• Annexes and test apparatus: Normative annexes include gas test chamber designs, impact apparatus, fire test room and defined smouldering test fires (e.g., TF2, TF3, TF9).

Practical applications - who uses this standard

• Manufacturers of CO fire detectors for product design, quality control and certification.
• Testing and certification laboratories performing type approval, factory acceptance and compliance testing.
• Fire alarm system designers and specifiers selecting detectors for building installations (commercial, industrial, car parks).
• Installers and maintenance providers ensuring correct placement, configuration and monitoring of detachable heads.
• Regulatory authorities and procurement teams referencing objective performance criteria in codes and tenders.

CO detectors are especially useful where smoke‑based detection is prone to false alarms (dust, steam, cooking vapours) and in applications such as car parks, loading docks and return‑air plenums - but care is needed where CO may be present from normal processes or where certain fires (e.g., non‑carbonaceous materials) produce little CO.

Related standards

• ISO 7240‑1 (General and definitions) and other parts of the ISO 7240 series (e.g., Part 8, Part 27)
• EN 50130‑4 (EMC immunity requirements)
• IEC 60068 family (environmental testing)