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PD ISO/TS 5660 — Reaction-to-Fire Tests Heat Release and Smoke Measurement Technical Specification Series
Reaction-to-Fire Tests — Heat Release, Smoke Production and Mass Loss Rate — Technical Specification Series Overview
🔥 PD ISO/TS 5660 is a BSI Published Document series adopting ISO technical specifications on “reaction-to-fire tests”, focused on measuring the three key combustion parameters of heat release, smoke production and mass loss rate. The series was prepared by BSI technical committee FSH/21 panel FSH/21/-/5 (Reaction to fire tests — heat release and smoke measurement) and carries ICS 13.220.50 (combustion of building materials and components). The cone calorimeter method is the core method basis; the series further provides measurement guidance and a method for low levels of heat release, delivering key data for material combustion evaluation, fire model inputs and fire design.
⚠️ Heat release rate (HRR) is one of the most important fire hazard parameters: it governs the rate of fire growth and smoke generation. Measurement accuracy directly affects the credibility of fire model predictions and component fire-performance judgements.
1. Series Structure and Scope 📌
This batch comprises two technical specifications, giving measurement guidance and a low heat release method:
| Part | Document | Subject | Main Content |
|---|---|---|---|
| Measurement guidance | PD ISO/TS 5660-3:2012 (ISO/TS 5660-3:2012) | Guidance on measurement | Capability and limitations of the cone calorimeter, calibration (heat flux meter, oxygen analyser), calibration frequency, measurement points |
| Low heat release | PD ISO/TS 5660-4:2016 (ISO/TS 5660-4:2016) | Measurement of low levels of heat release | Principle, apparatus, method for low HRR of low-combustibility materials, symbols and units |
💡 The two parts serve different needs: Part 3 helps laboratories run the cone calorimeter correctly and assure measurement quality; Part 4 pushes the measurement floor lower for low-combustibility materials, widening the applicability of the cone method.
2. Capability and Limitations of the Cone Calorimeter 🔬
Part 3 begins by defining the capability and limitations of the cone calorimeter:
- Capabilities: measure heat release rate, smoke production rate, mass loss rate and time to ignition of materials under radiant heating.
- Applications: provide data for material classification, product development, fire model inputs and performance-based design.
- Limitations: a small-scale test, it cannot fully represent ventilation, enclosure and fire-source conditions of real fires; extrapolation requires care.
- Test condition control: radiant flux, specimen orientation, ignition and exhaust flow directly affect results.
⚠️ Cone calorimeter results are valid for small specimens; extrapolation is affected by specimen thickness, backing conditions and ambient flux. Real component performance should be judged by combining other scales and fire models.
3. Calibration and Measurement Quality Control 📊
Part 3 systematically sets out cone calorimeter calibration requirements:
- Heat flux meter calibration: calibrate against a radiant heat flux standard to ensure accurate surface flux.
- Oxygen analyser calibration: the oxygen-consumption method relies on precise oxygen measurement; calibrate the analyser per procedure and check baselines.
- Calibration frequency: specify cycles and triggers for each calibration to give continuing assurance.
- Standard fuel verification: verify overall system accuracy using a standard fuel (e.g., methane).
✅ Calibration is the foundation of credible cone data: the heat flux meter sets the applied radiation and the oxygen analyser sets HRR calculation precision — both are indispensable and must be part of routine laboratory quality management.
4. Low Heat Release Measurement Method 🔥
Part 4 (2016) provides a method for low heat release of low-combustibility materials:
- Principle: optimise measurement sensitivity on the standard cone calorimeter to detect very low heat release rates.
- Apparatus requirements: higher demands on oxygen concentration resolution, gas flow stability and signal noise.
- Measurement procedure: specify sample preparation, conditioning, test procedure and data processing.
- Result expression: give units, symbols and uncertainty requirements for low-HRR results.
💡 Low heat release measurement suits the “low combustibility” evaluation of flame-retardant, building and interior materials; its value is quantitatively distinguishing “almost non-combustible” from “slightly combustible”, supporting finer material classification.
5. Engineering Practice Essentials 🛠️
- 🔍 Material evaluation: characterise material burning behaviour using HRR, smoke production rate and mass loss rate to aid selection and formulation.
- 🔧 Fire model inputs: provide key inputs such as HRR curves and smoke parameters for FDS and other fire simulations.
- 📊 Classification and certification: combine cone data with national building codes for material combustion performance evaluation and certification.
- 📋 Laboratory QC: build calibration and QC systems per Part 3 to ensure traceability.
6. Frequently Asked Questions ❓
❓ Q: Why does the cone calorimeter use the oxygen-consumption principle?
A: The heat released per unit mass of oxygen consumed is approximately constant; measuring exhaust oxygen concentration precisely lets HRR be inferred with high accuracy without measuring complex combustion products directly.
A: The heat released per unit mass of oxygen consumed is approximately constant; measuring exhaust oxygen concentration precisely lets HRR be inferred with high accuracy without measuring complex combustion products directly.
❓ Q: How does low heat release measurement differ from standard measurement?
A: The standard method targets general combustible materials; low-level measurement optimises oxygen resolution and signal processing so very low HRR can be reliably detected, for evaluating “almost non-combustible” materials.
A: The standard method targets general combustible materials; low-level measurement optimises oxygen resolution and signal processing so very low HRR can be reliably detected, for evaluating “almost non-combustible” materials.
❓ Q: Why is calibration frequency so important?
A: Heat flux meters and oxygen analysers drift with use; without periodic calibration, applied flux and HRR calculation develop systematic bias, making results incomparable and non-traceable.
A: Heat flux meters and oxygen analysers drift with use; without periodic calibration, applied flux and HRR calculation develop systematic bias, making results incomparable and non-traceable.
🔍 Q: Is the technical specification mandatory for laboratories?
A: Technical specifications are method-supplement and guidance documents; adoption depends on the laboratory quality system and specific test needs, but declaring ISO 5660 conformance implies following the relevant parts.
A: Technical specifications are method-supplement and guidance documents; adoption depends on the laboratory quality system and specific test needs, but declaring ISO 5660 conformance implies following the relevant parts.