ISO 16405:2015

Overview

ISO 16405:2015 - Room corner and open calorimeter: Guidance on sampling and measurement of effluent gas production using FTIR technique provides practical guidance on apparatus and procedures for collecting fire effluent gases and recording FTIR spectra during large-scale or simulated real-scale fire tests. The standard covers sampling from common fire-test configurations such as the room corner test (ISO 9705) and open calorimeter tests (ISO 24473). It focuses on the gas sampling system and the on-line FTIR measurement chain; spectral analysis and calibration are addressed separately in ISO 19702.

Key Topics and Technical Requirements

• FTIR-based on-line measurement: simultaneous, time-resolved concentration measurements of multiple infrared-active species using a heated optical cell and spectrometer.
• Gas sampling system components: probe, filter (particulate removal), heated tubing, pump and heated gas cell. All parts upstream of the FTIR cell must be heated to avoid condensation and loss of water‑soluble gases.
• Sampling system temperature: recommended heated sampling temperature range is 150 °C to 190 °C, with a homogeneous or slightly increasing temperature profile from probe to cell.
• Sampling positions and probe design:
  • Exhaust duct sampling (preferred for dilution and representative mixing) - mount probe where gases are uniformly mixed (typically several duct diameters downstream of bends).
  • Doorway / opening sampling - may require multi‑hole probes or traversing probes to obtain representative samples from non‑homogeneous flows.
  • Local point sampling - valid only for the specific local scenario being measured.
• Time resolution and transport delay: determined by extraction flow, duct/tubing transport time, residence time in the cell and FTIR acquisition rate. Response and delay times should be measured and reported.
• Measurement reporting: includes raw concentrations, conversion to total species production (requires volumetric flow measurement), and uncertainty estimation consistent with GUM principles.

Practical Applications and Who Uses It

ISO 16405 is used by:

• Fire test laboratories conducting full‑scale room corner and open calorimeter tests.
• Product manufacturers assessing fire toxicant production for materials and assemblies.
• Certification bodies and regulatory agencies evaluating fire hazard and toxic gas performance.
• Fire safety researchers and toxic gas analysts implementing FTIR sampling protocols for reproducible, quantitative effluent monitoring.

Benefits include improved reproducibility of effluent sampling, reduced matrix effects via appropriate sampling positions, and clear guidance for integrating FTIR instruments into fire testing workflows.

Related Standards

• ISO 19702 - Guidance for sampling and analysis of toxic gases and vapours in fire effluents using FTIR (spectral analysis and calibration)
• ISO 9705 - Full‑scale room test for surface products (room corner test)
• ISO 24473 - Open calorimetry - measurement of heat and combustion products
• ISO/IEC Guide 98‑3 (GUM) - Guide to the expression of uncertainty in measurement

Keywords: ISO 16405:2015, FTIR technique, effluent gas production, room corner test, open calorimeter, gas sampling probe, heated sampling system, fire testing.