SIST ISO 7971-1:2005

SLOVENSKI STANDARD
SIST ISO 7971-1:2005
01-junij-2005
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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
Ta slovenski standard je istoveten z: ISO 7971-1:2003
ICS:
67.060 äLWDVWURþQLFHLQSURL]YRGLL] Cereals, pulses and derived
QMLK products
SIST ISO 7971-1:2005 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ISO 7971-1:2005

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SIST ISO 7971-1:2005


INTERNATIONAL ISO
STANDARD 7971-1
First edition
2003-07-01


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 7971-1:2003(E)
©
ISO 2003

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SIST ISO 7971-1:2005
ISO 7971-1:2003(E)
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ii © ISO 2003 — All rights reserved

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SIST ISO 7971-1:2005
ISO 7971-1:2003(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 7971-1 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 4, Cereals
and pulses.
This first edition of ISO 7971-1 cancels and replaces ISO 7970:1986, which has been editorially revised. The
title has been changed to make it Part 1.
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: Routine method
© ISO 2003 — All rights reserved iii

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SIST ISO 7971-1:2005

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SIST ISO 7971-1:2005
INTERNATIONAL STANDARD ISO 7971-1:2003(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.
NOTE Several routine methods are used in different countries. A routine method for the determination of bulk density,
[1]
called “mass per hectolitre” utilizing a 1 litre measuring container is given in ISO 7971-2 .
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
mass per hectolitre
ratio of the mass of a cereal to the volume it occupies after being poured into a container under well-defined
conditions
NOTE It is expressed in kilograms per hectolitre at a stated moisture content.
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
The apparatus used shall comply with the following requirements, which correspond to those in OIML
[2]
Recommendations R 15 , and shall be similar to that shown in Figure 1.
NOTE For information, the requirements for the apparatus specified in this International Standard comply with those
[3]
prescribed in the relevant Council Directive of the European Communities .
4.2 Description and operation
4.2.1 Pre-filling measure
The pre-filling measure has a capacity of 24 l. Its internal form is a right circular cylinder with height
approximately equal to its diameter.
© ISO 2003 — All rights reserved 1

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SIST ISO 7971-1:2005
ISO 7971-1:2003(E)
Dimensions in millimetres

Figure 1 — Apparatus for determining bulk density of cereals
2 © ISO 2003 — All rights reserved

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SIST ISO 7971-1:2005
ISO 7971-1:2003(E)
Key
1 filling hopper 7 20 l measuring container 15 height of flow
2 truncated cone for guiding the 8 base support of measuring 16 wedged base support of
flow of grain container measuring container in filling
position
3 straightedge counterweight 9 tapered emptying tube
17 collecting box for surplus grain
4 guiding skirt for surplus grain 10 guiding collar for grain flow
18 distributor
5 guide by rail and rollers of the 11 shutter
frame of the straightedge 19 straightedge
12 frame of straightedge
6 removable part of skirt allowing 20 handle of wedge for base support
13 straightedge
the measuring container to be
14 straightedge counterweight
removed
NOTE This figure is for information only except for the dimensions shown, which are obligatory.
Figure 1 — Apparatus for determining bulk density of cereals (continued)
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 measure a quantity of grain greater than the capacity 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 capacity 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 trun
...