# Fertilisers (Sampling and Analysis) Regulations (Northern Ireland) 1996, Paragraph 6: PROCEDURE


Wash both sides of the sieves with water and place the sieve with 0.125 mm apertures above the 0.063 mm sieve.
Weigh to the nearest 0.05 g, 50 g of the prepared sample and place on the top sieve. Sieve under a small jet of cold water (tap water can be used) until the water is practically clear when it passes through. Care should be taken to ensure that the flow of water is such that the lower sieve never fills with water. When the residue on the top sieve seems to remain more or less constant, remove this sieve, and place on a collecting container (5.1) for the time being.
Continue the wet sieving through the lower sieve for a few minutes, until the water passing through is nearly clear. Replace the 0.125 mm sieve over the 0.063 mm sieve. Transfer any deposit from the collecting container to the top sieve and begin sieving again under a small jet of water until this water becomes almost clear once more.
Transfer each of the residues quantitatively into a separate 250 ml beaker by means of the funnel. Suspend each residue by filling the beakers with water. Allow to stand for about 1 minute and then decant as much water as possible. Place the beakers in the oven (5.3) at 150°C for two hours. Allow them to cool to room temperature in a desiccator, detach the residues with a brush and weigh them.

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Source: https://www.legislation.gov.uk/nisr/1996/513/schedule/2/part/I/chapter/13b./paragraph/6 (the official version)
Page: https://openlegislation.uk/fertilisers-sampling-and-analysis-regulations-northern-ireland-1996/schedule-2/part-I/chapter-13b./paragraph-6
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.