ISO INTERNATIONAL STANDARD 7837 Second edition 1992-07-01 ANsl nternat Doc Sec Fertilizers --. Determination of bulk density (loose) of fine-grained fertilizers Engrais -- Determination de la masse volumique sans fassement des engrais fins Reference number ISO 7837:1992(E) No reproduction or networking permitted without license from IHS Not for Resale ISO 7837:1992(E) Foreword Iso (the International Organization for Standardization) is a woridwide federation of national standards bodies (iso member bodies). The work of preparing International Standards is normally carried out through iso technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations. govern- mental and non-governmental, in liaison with Iso, also take part in the work. Iso collaborates closely with the Internationat Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an Inter- national Standard requires approval by at ieast 75 % of the member bodiescastingavote. Internationat Standard iso 7837 was prepared by Technical Committee ISO/TC 134, Fertilizers and soil conditioners, 'sub-Committee sc 3. Physical properties. This second edition cancels and replaces the first edition (Iso 7837:1983), which has been technically revised. ISO1992 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permissioninwriting fromthepublisher. International Organization for Standardization CasePostale56.CH-1211Geneve20·Switzerland Printed in Switzerland ii Copyright I ational Organizatio No reproduction or networking permitted without license from IHS Not for Resale ISO 7837:1992(E) Introduction A method for the determination of the bulk density (ioose) of solid ferti- lizers having particle sizes within the frequentiy encountered range from about 0,5 mm to 5 mm is specified in Iso 3944:1992, Fertilizers -Deter- mination of bulk density (loose). This method is not, however, suitable for fine-grained fertilizers having a large proportion of particles of di- ameters less than 0,5 mm. Such fertilizers pass with difficulty, in most cases, from the specified funnel into the measuring cylinder, generally cause considerable dust nuisance, and are inclined to form hollow spaces (air cavities) within their bulk volume. The bulk density values obtained are, thus, too low. In the case of fine-grained fertilizers, therefore, it is necessary to use a dust-tight, non-clogging apparatus, with a relatively wide measuring cylinder. ii Copyright Inte No reproduction or networking permitted without license from IHS Not for Resale