Carbon black content of plastics test instruments consists of:-
Electric Furnace, at least 20 cm (8 in.) long suitable for
use with the tubing described in 4.2.
Tubing,, 4 2.9 cm (1⁄8 in.) in diameter, approximately
twice as long as the furnace described in 4.1.
Stoppers—Two rubber or neoprene stoppers, to fit the
tube described in 4.2, unless the tube is fitted with ground