4.2.1 Principle
The test sample is heated at 250 °C 土 10 °C and the loss of mass from attached water is determined.
4.2.2 Apparatus
4.2.2.1 Heat-resistant container, for example with dimensions 200 mm x 150 mm x 30 mm and made from stainless steel.
4.2.3 Procedure
Heat the heat-resistant container at 250 °C 土 10 °C for 30 min. Cool in a desiccator, weigh and record its empty mass , m0, to the nearest 0,01 g.
Transfer the sample into the container and spread it out flat. Then weigh and record the mass, of the container and sample to the nearest 0,01 g.
Place the container without a lid in an air bath and heat it at 250 °C 土 10 °C for 16 h. Allow to cool in a desiccator. Weigh and record the mass,〜,of the container plus the dried sample to the nearest 0,01 g.