BS EN ISO 638-1:2021 pdf free

BS EN ISO 638-1:2021 pdf free.Paper, board, pulps and cellulosicna nomaterials — Determination of dry matter content by oven-drying method Part 1: Materials in solid form.
which can be read to the nearest 1 mg, for weighing test pieces of 2 g and less; for larger test pieces, which can be read to 0,05 % mass fraction of the original moisture-containing test piece.
5.2 Containers, water vapour-proof, with tightly fitting lids, and made from a material (e.g. glass or plastic) not affected by the conditions of test, previously dried to constant mass and weighed.
5.3 Drying oven, capable of maintaining the air temperature at 105 °C ± 2 °C, and suitably ventilated.
5.4 Desiccator.
6 Sampling
If the analysis is being done to evaluate a lot, obtain a representative sample of paper, board, or pulp as described in ISO 186 for paper and board or ISO 7213 for puips delivered in bales or rolls. For paper and board for recycling, sampling shall be in accordance with EN 17085.
If the tests are made on another type of sample, make sure the test pieces taken are representative of the sample received.
In all cases take special precautions to avoid any change in moisture or water content of the material that will be tested.
7 Preparation of test pieces
7.1 General
Protect the test pieces from evaporation. Do not use bare hands to handle the test pieces. Handle the test pieces and weighing containers with clean and dry plastic or rubber gloves or adapted tools (for example tweezers). For determination of the dry matter content of pulp, paper, board or cellulosic nanomaterial samples as received, place each test piece as soon as obtained in a water-vapour proof container and close it immediately as cellulosic materials and especially cellulosic nanomaterials are highly hygroscopic.
Prepare at least duplicate test pieces for each sample.
7.2 Paper and board for recycling
For paper and board for recycling, the test piece mass shall be in the range from 200 g (for a homogeneous mix of paper and board for recycling) up to 500 g (for a less homogeneous mix of paper and board for recycling), depending on the composition of the grade of paper and board for recycling.BS EN ISO 638-1 pdf free download.