DIN Standards Committee Food and Agricultural Products
DIN EN 12948
Liming materials - Determination of size distribution by dry and wet sieving; German version EN 12948:2010
Calcium-/Magnesium-Bodenverbesserungsmittel - Bestimmung der Korngrößenverteilung durch Trocken- und Nasssiebung; Deutsche Fassung EN 12948:2010
Overview
This European Standard specifies two methods for the determination of the particle size distribution of liming materials. The dry sieving method (method A) is applicable to all liming materials except wet and paste-like products. The wet sieving method (method B) is applicable to products which are susceptible to blinding, caking, electrostatic charges or agglomeration after pre-drying. The dry sieving of powdered material containing individual particles can be carried out quite easily. This method, which is described as method A in this document, is easy to handle, quick, cheap and enables the determination of the particle size of water-soluble materials. Therefore the dry sieving method should always be used first. However, the sieve apertures can become blocked by sample particles, a phenomenon known as blinding. Blinding is mainly caused by caking and the production of electrostatic charges, particularly on sieves with small apertures. Dry sieving of very wet material can also lead to blinding. These difficulties are not encountered with the wet sieving method, which is described as method B in this document, and which is applicable to any kind of material such as powders (dry or wet), paste-like products or granules except those containing water-soluble constituents. The European Standard has been prepared by CEN/TC 260 "Fertilizers and liming materials" (secretariat: DIN). National Mirror Committee is Working Committee NA 057-03-02 AA "Düngemittel" ("Fertilizers") of NAL.
