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ISO 712-2009 pdf free download

ISO 712-2009 pdf free download.Cereals and cereal products Determination of moisture content Reference method
Céréales et produits céréaliers — Determination de Ia teneur en eau — Methode de réference.
Products having parttcles of sizes less than or equal to 1,7 mm, where the mass fraction of particles with sizes over 1 mm is less than 10 % and where the mass fraction of particles with sizes less than 0,5 mm is more than 50 %, do not need to be ground before the determination.
Mix the laboratory sample thoroughly before taking the test portion (8.6.2.1).
B.6.1.2 Ground products
If the sample does not comply with the particle size characteristics mentioned In 8.6.1.1, grind it either without
preconditioning (B.6. 1.2.1) or with preconditioning (B.6. 1.2.2).
B.6.1 .2.1 Grinding without preconditioning
For products which are not likely to undergo variations in moisture content in the course of grinding (in general, products with a moisture content between 7 % and 17 %3) (see B.8.1)], carry out grinding without preconditioning.
Adjust the grinding mill (B.4.3) to obtain particles of the dimensions indicated in 8.6.1.1. grind a small quantity of the laboratory sample and discard it.
Then quickly grind about 3,5 g of the laboratory sample, and Immediately proceed in accordance with B.6.2.2.
B.6.1.2.2 Grinding with preconditioning
Products which are likely to undergo changes in moisture content in the course of grinding (in general. products with a moisture content greater than 17 %3)) shall be preconditioned so as to bring their moisture content to between 7 % and 17 %3) [if possible between 9 % and 15 % (see B.8.1)], before grinding.
If the moisture content is more than 17 %3) (the more frequent case), weigh, to the nearest 0,2 mg, about 3,59 of the laboratory sample. Record the mass as m. Calculate the mass of the test portion before preconditioning. m2, as the difference between rn and the mass of the dish, rnd
Then pre-dry the test portion in accordance with 7.3. except that the drying time shall be 1,5 to 2 h (see B.8.2) and it is unnecessary to renew the phosphorus pentaoxide.
If the moisture content is less than 7 %, prepare a test portion of about 3,5 g of the laboratory sample. Weigh it in the dish to the nearest 0.2 mg. Record the mass as m. Calculate the mass of the test portion before preconditioning, rn2, as the difference between m and the mass of the dish, rnd Then place the test portion and dish in a suitable atmosphere (usually that of the laboratory) and leave it to acquire a moisture content within the limits specified above.
After conditioning, weigh the sample to the nearest 0.2 mg. Record the mass as rn3. Calculate the mass of the test portion after preconditioning, rn3, as the difference between rn’3 and the mass of the dish, md Grind the test portion immediately in the grinding mill (8.4.3), adjusted to obtain particles of the dimensions indicated In B.6.1.1. and immediately proceed in accordance with 8.6.2.2.ISO 712-2009 pdf free download.

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