Document ID: chunk:federal_register_of_legislation:F2015C00542:reg:1:p3
Version: federal_register_of_legislation:F2015C00542
Segment Type: reg
Provision Reference: reg 1 (pt 3/43)
Character Range: 155139–157663

spanning the frame at 25-mm intervals over the bottom U-shaped frame (see Figure 19).
 The plane of the lower side of samples shall be 178 mm above the floor plate. The distance of the front edge of the sample holder from the end of the chamber shall be 22 mm; the distance of the longitudinal sides of the sample holder from the sides of the chamber shall be 50 mm (all inside dimensions). (See Figures 15 and 16).

*10.4.3. Gas burner
 The small ignition source is provided by a Bunsen burner having an inside diameter of 9.5 mm. It is so located in the test cabinet that the centre of its nozzle is 19 mm below the centre of the bottom edge of the open end of the sample (see Figure 16).
10.4.4. Test gas
 The gas supplied to the burner shall have a calorific value of about 38 MJ/m3 (for example natural gas).
10.4.5. Metal comb, at least 110 mm in length, with seven or eight smooth rounded teeth per 25 mm.

Figure 16

Example of combustion chamber

Figure 17

Typical drip pan

Figure 18

Example of sample holder

Figure 19

Example of section of lower U-frame design for wire support facility

10.4.6. Stop-watch, accurate to 0.5 sec.
10.4.7. Fume cupboard
 The combustion chamber may be placed in a fume-cupboard assembly provided that the latter's internal volume is at least 20 times, but not more than 110 times, greater than the volume of the combustion chamber and provided that no single height, width, or length dimension of the fume cupboard is greater than 2.5 times either of the other two dimensions.
 Before the test, the vertical velocity of the air through the fume cupboard shall be measured 100 mm forward of and to the rear of the ultimate site of the combustion chamber. It shall be between 0.10 and 0.30 m/s in order to avoid possible discomfort to the operator from combustion products. It is possible to use a fume cupboard with natural ventilation and an appropriate air velocity.
10.5. Samples
10.5.1. Shape and dimensions
 The shape and dimensions of samples are given in Figure 20. The thickness of the sample corresponds to the thickness of the product to be tested. It shall not be more than 13 mm. When sample-taking so permits, the sample shall have a constant section over its entire length. When the shape and dimensions of a product do not permit taking a sample of the given size, the following minimum dimensions shall be observed:
(a) For samples having a width of 3 to 60 mm, the length shall be 356 mm. In this case the material is tested over the product's width;
(b) For