BS476-6 Fire Propagation Index Tester for Building Materials and Structures
Introduction:
BS 476 part 6 specifies a method of test, the result is expressed as a fire propagation index, that provides a comparative measure of the contribution to the growth of fire made by an essentially flat material, composite or assembly. It is primarily intended for the assessment of the performance of the internal wall and ceiling linings.
During the test, the specimen is exposed to the tubular torch, heat release of the lamp is 530J / S. 2 minutes and 45 seconds later, the two electric heater was adjusted to 1800 watts in total, 5 minutes after starting the test, reduced the power to 1500 watts, keep the power not changed until finishing the experiment, the total test time is 20 minutes.
To assess the flame propagation properties of the material to be tested in BS476-6, thermocouple continuous recording chimney temperature and room temperature difference, and compared the results with the calibration curve, calibration curve based on the provisions of the density of asbestos - cement slab in the same measured way.
Comparing the temperature difference value of two curves which measured at the same time. In the first three minutes of the test, take the temperature difference value every 30 seconds, in the following 4-10 minutes, take the temperature difference value every one minute. In the last 11-20 minutes, take the temperature difference value every two minutes. The flame spread index of these three periods are calculated according to formula.
I is the value of sum of the three periods flame spread index. The higher of I value, the lower the material flame retardant, 0 grade material I≤12.
Standards:
BS 476 Part 6 A1: 2009
GB/T 17658-1999
Features:
1, Stainless steel support frame and Calcium silicate board combustion chamber.
2, Three kinds of sample holders for different thickness of the specimens.
3, Low reflective black finished mild steel Chimney and Cowl assembly complete with thermocouple mounting points.
4, Compliant stainless steel gas burner.
5, Two K type mineral insulated thermocouples complete with ceramic insulators.
6, Two pencil type heaters with 1000w installed in combustion chamber.
7, Control gas instrumentation including electronic gas on/off valve, flow regulating valve, flow meter and manometer.
8, Intelligent single phase power controller with feedback loop for accurate control of electric heating elements
9, DAQ record automatically the mV output from the thermocouples of the flue gases throughout the duration of the test.
10, According to the test time, automatically adjust the output power.
