ISO 7240-12:2022

Overview

ISO 7240-12:2022 - Fire detection and alarm systems - Part 12: Line type smoke detectors using a transmitted optical beam - defines requirements, test methods and performance criteria for line‑type smoke detectors that operate by sensing attenuation or changes in attenuation of a transmitted optical beam. The standard applies to detector assemblies with at least a transmitter and a receiver (and optionally reflectors) used in fire detection and alarm systems installed in buildings. The term “optical” covers the part of the electromagnetic spectrum to which the receiver responds (not limited to visible light).

Note: ISO 7240-12:2022 excludes detectors with opposed components separated by less than 1 m, detectors whose optical path is set by an integral mechanical connection, and detectors with special characteristics not assessable by the specified test methods.

Key topics and technical requirements

ISO 7240-12:2022 covers both functional requirements and extensive testing. Key topics include:

• Conformance and performance criteria for line‑type optical beam detectors.
• Individual alarm indication and monitoring of detachable detectors and connections.
• Connection of ancillary devices and fault signalling requirements.
• Manufacturer and on‑site adjustment of response threshold values and limits of compensation.
• Protection of optical components and alignment considerations.
• Requirements for software‑controlled detectors, including documentation and storage of programs/data.
• Comprehensive test methods, for example:
  • Atmospheric, mounting and operating conditions
  • Measurement of response value, reproducibility and repeatability
  • Alignment dependence and optical path length dependence
  • Rapid and slow changes in attenuation and fire sensitivity tests
  • Environmental endurance tests (heat, cold, damp heat, vibration, EMC immunity, SO2 corrosion, impact)
• Test reporting, marking and data provisions for certification and documentation.

Practical applications and who uses this standard

ISO 7240-12:2022 is essential for:

• Manufacturers of line‑type optical beam smoke detectors to demonstrate product compliance.
• Fire detection system designers and integrators specifying detectors for building projects.
• Certification and test laboratories performing performance and environmental testing.
• Installers, building owners and fire safety engineers who require validated detector performance and reliable fault/alarms behavior.
• Regulators and authorities having jurisdiction (AHJs) seeking standardized test evidence for approvals.

Using ISO 7240-12 helps ensure consistent detection performance, reduced false alarms, reliable fault detection and documented test evidence for long‑range optical beam fire detection.

Related standards

ISO 7240-12:2022 is part of the ISO 7240 series on fire detection and alarm systems. Refer to other parts of the ISO 7240 family for complementary requirements on point smoke detectors, heat detectors, system requirements, and installation practices.