EN ISO 7971-1:2009
(Main)Cereals - Determination of bulk density, called mass per hectolitre - Part 1: Reference method (ISO 7971-1:2009)
Cereals - Determination of bulk density, called mass per hectolitre - Part 1: Reference method (ISO 7971-1:2009)
ISO 7971-1:2009 specifies the reference method for the determination of bulk density, called “mass per hectolitre”, of cereals as grain.
Getreide - Bestimmung der Schüttdichte, sogenannte Masse je Hektoliter - Teil 1: Referenzverfahren (ISO 7971-1:2009)
Dieser Teil von ISO 7971 legt das Referenzverfahren zur Bestimmung der Schüttdichte, der sogenannten „Masse je Hektoliter“, von Getreidekörnern fest.
ANMERKUNG In verschiedenen Ländern werden unterschiedliche Routineverfahren angewendet. Ein Routinever¬fahren zur Bestimmung der Schüttdichte, der sogenannten „Masse je Hektoliter“, ist in ISO 7971 3 angegeben.
Céréales - Détermination de la masse volumique, dite masse à l'hectolitre - Partie 1: Méthode de référence (ISO 7971-1:2009)
L'ISO 7971-1:2009 spécifie la méthode de référence de détermination de la masse volumique, dite «masse à l'hectolitre», des céréales en grain.
Žita - Določanje prostorninske mase, imenovane hektolitrska masa - 1. del: Referenčna metoda (ISO 7971-1:2009)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2009
äLWD'RORþDQMHSURVWRUQLQVNHPDVHLPHQRYDQHKHNWROLWUVNDPDVDGHO
5HIHUHQþQDPHWRGD ,62
Cereals - Determination of bulk density, called mass per hectolitre - Part 1: Reference
method (ISO 7971-1:2009)
Getreide - Bestimmung der Schüttdichte, so genannte Masse je Hektoliter - Teil 1:
Referenzverfahren (ISO 7971-1:2009)
Céréales - Détermination de la masse volumique, dite masse à l'hectolitre - Partie 1:
Méthode de référence (ISO 7971-1:2009)
Ta slovenski standard je istoveten z: EN ISO 7971-1:2009
ICS:
67.060 äLWDVWURþQLFHLQSURL]YRGLL] Cereals, pulses and derived
QMLK products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN ISO 7971-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2009
ICS 67.060
English Version
Cereals - Determination of bulk density, called mass per
hectolitre - Part 1: Reference method (ISO 7971-1:2009)
Céréales - Détermination de la masse volumique, dite Getreide - Bestimmung der Schüttdichte, sogenannte
masse à l'hectolitre - Partie 1: Méthode de référence (ISO Masse je Hektoliter - Teil 1: Referenzverfahren (ISO 7971-
7971-1:2009) 1:2009)
This European Standard was approved by CEN on 8 August 2009.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 7971-1:2009: E
worldwide for CEN national Members.
Contents Page
Foreword .3
Foreword
This document (EN ISO 7971-1:2009) has been prepared by Technical Committee CEN/TC 338 “Cereal and
cereal products”, the secretariat of which is held by AFNOR, in collaboration with Technical Committee
ISO/TC 34 "Food products".
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by February 2010, and conflicting national standards shall be withdrawn
at the latest by February 2010.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
INTERNATIONAL ISO
STANDARD 7971-1
Second edition
2009-08-15
Cereals — Determination of bulk density,
called mass per hectolitre —
Part 1:
Reference method
Céréales — Détermination de la masse volumique, dite masse à
l'hectolitre —
Partie 1: Méthode de référence
Reference number
ISO 7971-1:2009(E)
©
ISO 2009
ISO 7971-1:2009(E)
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ii © ISO 2009 – All rights reserved
ISO 7971-1:2009(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide 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, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 7971 (all parts) was prepared by the European Committee for Standardization (CEN) Technical
Committee CEN/TC 338, Cereal and cereal products, in collaboration with Technical Committee ISO/TC 34,
Food products, Subcommittee SC 4, Cereals and pulses, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 7971-1:2003), which has been revised to take
account of ISO 7971-2:2009.
ISO 7971 consists of the following parts, under the general title Cereals — Determination of bulk density,
called mass per hectolitre:
⎯ Part 1: Reference method
⎯ Part 2: Method of traceability for measuring instruments through reference to the international standard
instrument
⎯ Part 3: Routine method
INTERNATIONAL STANDARD ISO 7971-1:2009(E)
Cereals — Determination of bulk density, called mass
per hectolitre —
Part 1:
Reference method
1 Scope
This part of ISO 7971 specifies the reference method for the determination of bulk density, called “mass per
hectolitre”, of cereals as grain.
NOTE Several routine methods are used in different countries. A routine method for the determination of bulk density,
called “mass per hectolitre”, is given in ISO 7971-3.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
bulk density
“mass per hectolitre”
〈cereals〉 ratio of the mass of a cereal to the volume it occupies after being poured into a container under well-
defined conditions
NOTE 1 Bulk density is expressed in kilograms per hectolitre of grain as received.
NOTE 2 The bulk density, as defined in this part of ISO 7971, is different from “packing density” or “intrinsic density” of
cereals.
3 Principle
A sample is poured in a controlled manner from a hopper into a 20 l container, which is then weighed.
4 Requirements for apparatus
4.1 General
[2]
The apparatus used shall comply with the following requirements, which correspond to those in OIML R 15 ,
and shall be similar to that shown in Figure 1.
ISO 7971-1:2009(E)
Dimensions in millimetres
Figure 1 — Apparatus for determining bulk density of cereals (continued)
2 © ISO 2009 – All rights reserved
ISO 7971-1:2009(E)
Key
1 filling hopper 11 shutter
2 truncated cone for guiding the flow of grain 12 frame of straightedge
3 straightedge counterweight 13 straightedge
4 guiding skirt for surplus grain 14 straightedge counterweight
5 guide by rail and rollers of the frame of the straightedge 15 height of flow
6 removable part of skirt allowing the measuring container 16 wedged base support of measuring container in filling
to be removed position
7 measuring container, volume 20 l 17 collecting box for surplus grain
8 base support of measuring container 18 distributor
9 tapered emptying tube 19 straightedge
10 guiding collar for grain flow 20 handle of wedge for base support
NOTE This figure is for information only except for the dimensions shown, which are obligatory.
Figure 1 — Apparatus for determining bulk density of cereals
4.2 Description and operation
4.2.1 Pre-filling container. The pre-filling measure has a nominal volume of 24 l. Its internal form is a right
circular cylinder with height approximately equal to its diameter.
4.2.2 Filling hopper. The hopper has the shape of a truncated vertical circular cone surmounted by a
cylindrical rim. Its lower part terminates in an axial tube with a slightly tapering bore, the wider end of which is
at the bottom. A shutter, hinge-mounted on the tube and able to close the tube completely, controls the
emptying process.
The hopper receives from the pre-filling container a quantity of grain greater than the content of the measuring
container.
4.2.3 Distributor. The distributor is an inverted circular mushroom-shaped element connected to the
bottom end of a vertical rod positioned in the axis of the hopper.
The rod lowers the distributor inside the tapered tube to an adjustable level from top to bottom to allow
adjustment of the apparatus: lowering the distributor increases the rate of flow of the grain, which collects in
greater quantity owing to compaction in the measuring container, thus giving higher results; conversely, the
results are lower when the distributor is raised.
4.2.4 Measuring container. The measuring container has a nominal volume of 20 l. Its internal form is a
right circular cylinder with height approximately equal to its diameter. Its upper edge is ground flat.
4.2.5 Base support for the measuring container. A base on rails supports the container and allows it to
travel underneath the hopper, in the axis of which it can be locked, or taken out of the chassis for easy
removal.
4.2.6 Protection and guiding collar for grain flow. A cylindrical collar, of the same diameter as the
measuring container, is placed between the hopper and the measuring container, leaving a horizontal space
between its lower edge and the upper edge of the container to allow the passage of a straightedge.
During filling, the collar, which is surmounted by a truncated cone-shaped section, protects the grain as it
drops and at the end retains the surplus grain.
4.2.7 Straightedge (levelling blade). The straightedge is a flat, thin but rigid steel blade, sharpened to the
form of an open V at the front. It is fixed horizontally in a frame mounted on rollers and driven in its plane by a
counterweight.
ISO 7971-1:2009(E)
The frame guides the straightedge across the grain in the gap between the collar and the upper edge of the
measuring container. The movement shall be continuous and not jerky, and the straightedge shall touch
neither the collar nor the container.
In its movement, the straightedge levels the grain to the level of the measuring container, thus giving a
determined volume.
4.2.8 Collecting box for surplus grain. At the same time as levelling the grain, the straightedge also
closes off the lower surface of the collar as it removes from the container any grain surplus to its volume.
When the straightedge is drawn back, with the container removed, this surplus grain falls into a collecting box
placed beneath the base of the container and towards which the grain is guided by a skirt.
4.2.9 Overall assembly. The apparatus is assembled in a rigid chassis equipped with a verticality
adjustment screw; verticality is checked by means of a plumbline or a spirit-level.
The hopper with its tube and distributor, the collar and the mea
...
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