Paragraph 5 PROCEDURE

Weigh the sample portion (4.1 or 4.2) to the nearest 0.01 g and transfer to a 500 ml flask. Add approximately 300 ml of de-mineralized water, stopper and shake vigorously by hand for 30 seconds. Remove the stopper for an instant to relieve the pressure and replace the stopper. Place the flask in the rotating end over end shaker (3.5) and shake for 60 minutes to ensure the complete suspension of the sample.

Assemble the three sieves (3.2) in ascending order of aperture size on top of the receiver.

Rinse the sample quantitatively onto the top sieve and wash under a flow of water up to 2.5 litres/min until no more material passes each sieve, or up to a maximum time period of 10 minutes.

Remove the sieves and rinse the residue on each sieve quantitatively into a separate 250 ml beaker. Decant most of the water from the top of the material and dry each of the oversize fractions in an oven set at 105°C and weigh each fraction separately.