ISO 834-2:2019

Overview

ISO 834-2:2019 - Fire-resistance tests - Elements of building construction - Part 2 - specifies requirements and recommendations for measuring furnace exposure on test samples used with ISO 834-1 fire-resistance tests. The standard defines how to monitor temperature, air velocity and oxygen content near the surface of simulated samples (a gypsum-board face on cold‑formed steel supports) to assess the uniformity of furnace exposure. It focuses on instrumentation, sensor locations, and supporting construction; it does not set furnace performance requirements. Informative Annex A explains the intended use of the generated data and the rationale for the instrumentation.

Key topics and requirements

• Supporting construction: Simulated samples use cold-formed steel supports faced with two layers of gypsum board (minimum 15 mm on the exposed side) and a structural panel (minimum 15 mm) on the unexposed side. Support channel thickness and dimensions are specified for horizontal and vertical constructions. Typical fastener spacing and screw details are provided.
• Instrumentation types:
  • Plate thermometers (minimum five) mounted on the exposed gypsum surface.
  • Bi-directional low‑velocity probes with fast-response Type K (chromel‑alumel) ungrounded thermocouples (nickel‑chromium sheath, ≤1.5 mm diameter) for local pressure and temperature measurements.
  • Oxygen-content probe (T probe) conforming to ISO 834-1.
• Sensor placement: Instruments are positioned within the defined effective area of the furnace opening; plate thermometers are placed at corners and center for smaller openings (≤1 700 × 1 700 mm). Laboratory-determined margin dimensions (L) define where edge effects are insignificant (each L ≤ 1 700 mm).
• Measurement and calculations: Gas velocity is calculated from the measured pressure differential and thermocouple temperature using the prescribed formula. Data recording is required at a minimum of 1‑minute intervals; test duration for exposure measurement is at least 45 minutes.
• Documentation: The test report must include all relevant specimen and test details, instrumentation layout and recorded data.

Applications and users

ISO 834-2:2019 is used to:

• Validate and certify fire-resistance tests by ensuring uniform furnace exposure.
• Generate reproducible exposure-characterization data for research, laboratory calibration and standards compliance. Key users:
• Fire‑resistance testing laboratories and technicians
• Fire safety engineers and consultants
• Product manufacturers (doors, walls, partitions, linings)
• Building code authorities and certification bodies

Related standards

• ISO 834-1 (General requirements for fire-resistance tests) - instrumentation for oxygen probe and furnace operation references.
• National and regional test methods that reference ISO 834 series for furnace exposure characterization.

Keywords: ISO 834-2:2019, fire-resistance tests, furnace exposure measurement, instrumentation, gypsum board, bi-directional probe, plate thermometer, air velocity, oxygen content, fire safety testing.