ISO/TS 19850:2022

Overview

ISO/TS 19850:2022 provides methodologies to validate the use of LED (light-emitting diode) light sources as alternatives to traditional white light (gas-filled tungsten incandescent lamps) for measuring smoke parameters in fire tests. The technical specification focuses on comparing measurements of smoke density, optical density, transmittance, and smoke production rate obtained with LEDs against those obtained with conventional white light systems. Its purpose is to identify suitable LED sources that produce equivalent measurement results for established fire-test apparatus.

Key topics and requirements

• Purpose and scope: Defines the approach to compare LED-based measurements with white-light baselines used in smoke extinction methods.
• Measurement principles: Covers definitions (opacity, optical density, transmittance, smoke production rate) and the general measurement principle used in existing standards.
• Spectral comparison: Procedures for comparing the spectral distributions of candidate LEDs with original white light sources to assess suitability.
• Apparatus-specific methods: Guidance for adapting and comparing LEDs in apparatus specified in standards such as ISO 9705-1, ISO 24473, ISO 9239-1, EN 13823 and IEC 61034-1. Two comparison approaches (Method A - preferred - and Method B) are described.
• Alternative experimental setup: A dedicated test arrangement (smoke generator, ducts, light source system) for controlled comparison when in-situ replacement is impractical.
• Calibration and measurement fidelity: References to the light-receiving system (achromatic lenses, silicon photo-diodes with spectral filters) and calibration practices (neutral density filter checks, measurement accuracy requirements).
• Data comparison and analysis: Procedures for comparing transmission and derived smoke parameters between LED and white-light systems.

Applications and users

ISO/TS 19850:2022 is intended for:

• Fire test laboratories transitioning to LED light sources for smoke measurement.
• Manufacturers of smoke-measurement instruments and LED light sources seeking compliance guidance.
• Standards committees and test-house engineers updating test rigs in standards such as ISO 9239-1 or IEC 61034-1.
• Building safety engineers and product certification bodies who rely on consistent smoke measurement data for materials and product testing.

Practical benefits include future-proofing test apparatus as incandescent white lamps are phased out and ensuring continuity and comparability of smoke measurement data when using LEDs.

Related standards

• ISO 9239-1, ISO 9705-1, ISO 24473 (fire test methods using light extinction)
• IEC 61034-1 (smoke density test apparatus)
• EN 13823, EN 50399 (building product reaction-to-fire tests and calibration)
• ISO 3182 (light-receiving system specifications)

Keywords: ISO/TS 19850:2022, LED smoke measurement, smoke density, smoke production rate, white light replacement, fire tests, optical density, transmittance.