Polyolefin pipes and fittings — Determination of carbon black content by calcination and pyrolysis — Test method and basic specification

The determination is carried out by pyrolysis of a test portion at 550 °C in nitrogen followd by a calcination in a muffle furnace at 900 °C. The carbon black content is calculated from difference in mass before and after calcination. When so determined the carbon black content in polyethylen pipe material shall be 2,5 0,5 % (m/m).