CONVECTIVE HEAT. DETERMINING A FLAME’S CONVECTIVE HEAT TRANSFER
The EN ISO 9151 standard specifies the test method to determine heat transfer through a material or set of materials used in protective clothing. Materials will be classified based on heat transfer rates, which indicate relative heat transfer under specific testing conditions.
EN ISO 9151 TEST METHOD CERTIFICATION REQUIREMENTS
EN ISO 1951
For each material or set of materials, a minimum of 3 samples (140 mm x 140 mm) will be tested.
Test: a fabric sample will be subjected to an incident heat flow of 80 kW/m² ± 5%. The heat that passes through the sample is measured using a calorimeter located above, and in contact with, the fabric sample.
The time in seconds needed for the calorimeter’s temperature to increase 24 ºC ± 0.2 ºC is measured.
When multilayered sets are tested, the fabrics should follow the order in which they will be made.
1 Thermocouple
2 Calorimeter block
3 Sample
The heat transmission rate must not be deemed as a measurement of the protection time provided by tested materials under real usage conditions.