BS476-6 Fire Propagation Index Tester for Building Materials and Structures
BS 476-6 is a test method of measuring the flame propagation properties of materials, primarily for fire protection performance evaluation of the walls and ceilings, measurement results are expressed as an index of flame propagation.
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.
BS 476 Part 6 A1: 2009
1. Stainless steel cabinet support frame;
2. Calcium silicate board combustor;
3. All the three sample holders are stainless steel parcel;
4. 2 sets 1000W quartz radiation device, to provide thermal radiation to samples;
5. T-type burner supply flame combustion to the sample;
6. Thermocouple continuous recording temperature and room temperature difference value in chimney;
7. The power output is automatically controlled according to the test of time;
8. The computer automatically processes the data, and print test report;