6770 International Standard (ISO INTE RNATIONAL ORGANIZATION FOR STANDARDIZATION MEXAYHAPOAHAR OPrAHW3ALWR HO CTAHAAPTM3AUWMORGANISATION INTERNATIONALE DE NORMALISATION Instant tea - Determination of free-flow and compacted bulk densities The soluble - Détermination de la masse volumique sans tassement et apres tassement First edition - 1982-09-15 UDC 663.958 : 531.755 Ref. No. 1SO 6770-1982 (E) :0 6770-1982 (E) Descriptors : agricultural products, tea, tests, determination, density (mass/volume), settling, sampling, test results. Price based on 6 pages edwithout licensefrom IHS Not for Resale Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards institutes (IsO member bodies). The work of developing Inter- national Standards is carried out through iSo technical committees. Every member body interested in a subject.for which a technical committee has been set up has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with Iso, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. International Standard ISO 6770 was developed by Technical Committee ISO/TC 34, Agricultural food products, and was circulated to the member bodies in March 1981. It has been approved by the member bodies of the following countries : Iraq Australia South Africa, Rep. of Austria Israel Spain Chile Kenya Sri Lanka Czechoslovakia Korea, Rep. of Switzerland Egypt, Arab Rep. of Netherlands Tanzania New Zealand United Kingdom France Germany, F. R. Peru USA Hungary Philippines USSR India Romania Yugoslavia No member body expressed disapproval of the document. International Organization for Standardization, 1982 Printed in Switzerland Copyright International Organization for Standardization Not for Resale g permitted without license from IHS INTERNATIONAL STANDARD ISO 6770-1982 (E) Instant tea - Determination of free-flow and compacted bulk densities O Introduction little dependent on the human factor as possible. It is also im- portant that any mechanical apparatus needed is standardized, A knowledge of the bulk density of instant tea is essential to cheap, and easily available throughout those parts of the world trade in that commodity for it determines the volume occupied where instant tea is produced or sold. by a given mass and hence is an important factor in filling jars correctly for retail sale, and for controlling the mass of instant tea delivered from vending machines. Scope and field of application Bulk density is defined as the ratio of mass to volume. The This International Standard specifies two methods for the volume of a given sample of instant tea varies according to its determination of the bulk density of instant tea : history of handling, due to compaction (reversible) and powder breakdown (irreversible) effects. Bulk densities can be ex- a) free-flow bulk density (section one); pressed in two ways : free-flow (or uncompacted) density and b) compacted bulk density (section two). tapped (or compacted)density. Instant tea is fragile and subject to irreversible powder 2 Reference breakdown effects which may occur with repetitive determina- tion of compacted bulk density. Because both densities (and in ISo 787/11, General methods of test for pigments and ex- particular the compacted density) depend so critically on the methods used for handling, it is particularly important that the tenders - Part 11: Determination of tamped volume and ap- methods adopted for their measurement be as simple and as parent density after tamping. Copyright International Organization for Standardization reproduction or networking permitted without license from IHS Not for Resale