ISO 3086:1998

Iron ores — Experimental methods for checking the bias of sampling

Minerais de fer — Méthodes expérimentales de contrôle de l'erreur systématique d'échantillonnage

Železove rude - Eksperimentalne metode za preverjanje pravilnosti vzorčenja

General Information

• Status: Withdrawn
• Publication Date: 18-Feb-1998
• Withdrawal Date: 18-Feb-1998
• ICS: 73.060.10 - Iron ores
• Technical Committee: ISO/TC 102/SC 1 - Sampling
• Drafting Committee: ISO/TC 102/SC 1 - Sampling
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 19-Apr-2006
• Ref Project: SIST ISO 3086:2000 - Iron ores -- Experimental methods for checking the bias of sampling

Relations

• Revised: ISO 3086:2006 - Iron ores — Experimental methods for checking the bias of sampling
• Effective Date: 15-Apr-2008
• Revises: ISO 3086:1986 - Iron ores — Experimental methods for checking the bias of sampling
• Effective Date: 15-Apr-2008

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 3086
Third edition
1998-02-15
Iron ores — Experimental methods for
checking the bias of sampling
Minerais de fer — Méthodes expérimentales de contrôle de l'erreur
systématique d'échantillonnage
A
Reference number
ISO 3086:1998(E)

---------------------- Page: 1 ----------------------
ISO 3086:1998(E)
Contents
1 Scope .1
2 Normative references .1
3 Definitions .1
4 Principle.2
5 General conditions .2
6 Sampling and sample preparation methods.2
6.1 Sampling.2
6.2 Sample preparation .2
7 Analysis of experimental data .3
7.1 Determination of the standard deviation of the differences.3
7.2 Determination of the confidence interval for d .3
7.3 Statistical analysis.4
8 Test report .5
Annexes
A Flow sheet of the statistical analysis.6
B Numerical examples of experiments.7
©  ISO 1998
All rights reserved. Unless otherwise specified, 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 permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet [e-mail]
X.400 c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
ii

---------------------- Page: 2 ----------------------
© ISO
ISO 3086:1998(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.
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.
International Standard ISO 3086 was prepared by Technical Committee ISO/TC 102, Iron ores, Subcommittee
SC 1, Sampling.
This third edition cancels and replaces the second edition (ISO 3086:1986), which has been technically revised.
Annex A forms an integral part of this International Standard. Annex B is for information only.
iii

---------------------- Page: 3 ----------------------
©
INTERNATIONAL STANDARD  ISO ISO 3086:1998(E)
Iron ores — Experimental methods for checking the bias of
sampling
1 Scope
This International Standard specifies experimental methods for checking the bias of the sampling of
iron ores, when the sampling is carried out in accordance with the methods specified in ISO 3081 or
ISO 3082, having as reference a stopped-belt sampling method according to ISO 3081.
NOTES
1 Sampling systems not completely in accordance with ISO 3081 or ISO 3082 are not always expected to
be biased. Therefore bias checking may be done when there is some disagreement about the importance of
some departure from the conditions of ISO 3081 and ISO 3082. If one party argues that the bias is likely to be
substantial under some particular set of conditions then bias testing should mostly be done when those
conditions apply.
2 The method for analysis of experimental data described here may also be applied:
a) for checking the bias of sample preparation of iron ores, having as reference the methods for sampling
preparation according to ISO 3082 and ISO 3083;
b) for checking a possibly significant difference in the results obtained from the samples of one lot
collected at different places, for example, a loading point and unloading point.
2 Normative references
The following Standards contain provisions which, through reference in the text, constitute provisions
of this International Standard. At the time of publication, the editions indicated were valid. All Standards
are subject to revision, and parties to agreements based on this International Standard are encouraged
to investigate the possibility of applying the most recent editions of the Standards indicated below.
Members of IEC and ISO maintain registers of currently valid International Standards.
1)
ISO 3081:1986 , Iron ores — Increment sampling — Manual method.
1)
ISO 3082:1987 , Iron ores — Increment sampling and sample preparation — Mechanical method.
1)
ISO 3083:1986 , Iron ores — Preparation of samples — Manual method.
ISO 3085:1996, Iron ores — Experimental methods for checking the precision of sampling.
ISO 11323:1996, Iron ores — Vocabulary.
3 Definitions
For the purposes of this International Standard, the definitions given in ISO 11323 apply.
———————
1)  To be revised and published as ISO 3082.
1

---------------------- Page: 4 ----------------------
©
ISO
ISO 3086:1998(E)
4 Principle
The results obtained from the method to be checked (referred to as method B) are compared with the
results of a reference method (referred to as method A) which is considered to produce practically
unbiased results, from technical and empirical viewpoints.
In the event of there being no significant difference, in a statistical sense, between the results obtained
by method B and method A, method B may be adopted as a routine method. This difference is
assessed by comparing a 90 % confidence interval for the true average bias with the relevant bias,
d
(see 5.2).
5 General conditions
5.1  The number of lots to be tested shall be not less than ten. The number of further tests required
depends on the confidence interval for the true average bias, based on at least ten tests, and the value
of the relevant bias, d.
5.2  The relevant bias, d, which is considered large enough to justify the likely expense of reducing the
average bias, shall be decided beforehand. As a guide, d is likely to be less than s , the standard
SPM
deviation for sampling, sample preparation and measurement, determined according to ISO 3085.
NOTE —  If the experiment is aimed at checking the sample preparation only, the value of d is likely to be
less than s , determined according to ISO 3085.
PM
5.3  Quality characteristics such as total iron content, moisture content, size distribution and physical
properties may be used.
6 Sampling and sample preparation methods
6.1 Sampling
The reference method, method A, for checking the bias of sampling is a stopped-belt sampling method
according to ISO 3081.
Method A: take each increment from the full width and thickness of the ore stream on the stopped
conveyor at a specified place for a length of belt more than three times the nominal top size or
30 mm, whichever is the greater.
The method to be checked, method B, carried out according to ISO 3081 or ISO 3082, shall be
compared with method A for the same material.
Method B: sampling methods such as sampling from moving conveyors with a mechanical
sampler and sampling during the transfer to or from ships and wagons are examples of method B.
6.2 Sample preparation
Methods for making up a pair of gross samples, preparation of samples and testing shall be as given in
6.2.1 to 6.2.3.
6.2.1  Increments obtained from one lot, in accordance with method A and method B, are made up into
two gross samples, A and B.
6.2.2  The gross samples, A and B, are subjected, in the same manner, to sample preparation as
specified in ISO 3082 or ISO 3083 and tested as specified in the relevant International Standards
separately, and a pair of measurements obtained.
2

---------------------- Page: 5 ----------------------
©
ISO
ISO 3086:1998(E)
6.2.3  The above procedure is performed on ten or more lots (see 5.1).
NOTES
1 When increments for method A and method B can be taken from closely adjacent portions of the ore, it is
recommended that sample preparation and testing be carried out on individual increments or on combinations of
a small number of adjacent increments. This allows comparisons of ten or more pairs of measurements to be
made more quickly than if measurements were only made on entire lots. The above comparison of
measurements should be made on pairs of increments taken from several lots, preferably of the same type of
ore. However, it is not permitted to combine a number of paired res
...

SLOVENSKI STANDARD
SIST ISO 3086:2000
01-junij-2000
äHOH]RYHUXGH(NVSHULPHQWDOQHPHWRGH]DSUHYHUMDQMHSUDYLOQRVWLY]RUþHQMD
Iron ores -- Experimental methods for checking the bias of sampling
Minerais de fer -- Méthodes expérimentales de contrôle de l'erreur systématique
d'échantillonnage
Ta slovenski standard je istoveten z: ISO 3086:1998
ICS:
73.060.10 Železove rude Iron ores
SIST ISO 3086:2000 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST ISO 3086:2000

---------------------- Page: 2 ----------------------

SIST ISO 3086:2000
INTERNATIONAL ISO
STANDARD 3086
Third edition
1998-02-15
Iron ores — Experimental methods for
checking the bias of sampling
Minerais de fer — Méthodes expérimentales de contrôle de l'erreur
systématique d'échantillonnage
A
Reference number
ISO 3086:1998(E)

---------------------- Page: 3 ----------------------

SIST ISO 3086:2000
ISO 3086:1998(E)
Contents
1 Scope .1
2 Normative references .1
3 Definitions .1
4 Principle.2
5 General conditions .2
6 Sampling and sample preparation methods.2
6.1 Sampling.2
6.2 Sample preparation .2
7 Analysis of experimental data .3
7.1 Determination of the standard deviation of the differences.3
7.2 Determination of the confidence interval for d .3
7.3 Statistical analysis.4
8 Test report .5
Annexes
A Flow sheet of the statistical analysis.6
B Numerical examples of experiments.7
©  ISO 1998
All rights reserved. Unless otherwise specified, 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 permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet [e-mail]
X.400 c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
ii

---------------------- Page: 4 ----------------------

SIST ISO 3086:2000
© ISO
ISO 3086:1998(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.
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.
International Standard ISO 3086 was prepared by Technical Committee ISO/TC 102, Iron ores, Subcommittee
SC 1, Sampling.
This third edition cancels and replaces the second edition (ISO 3086:1986), which has been technically revised.
Annex A forms an integral part of this International Standard. Annex B is for information only.
iii

---------------------- Page: 5 ----------------------

SIST ISO 3086:2000

---------------------- Page: 6 ----------------------

SIST ISO 3086:2000
©
INTERNATIONAL STANDARD  ISO ISO 3086:1998(E)
Iron ores — Experimental methods for checking the bias of
sampling
1 Scope
This International Standard specifies experimental methods for checking the bias of the sampling of
iron ores, when the sampling is carried out in accordance with the methods specified in ISO 3081 or
ISO 3082, having as reference a stopped-belt sampling method according to ISO 3081.
NOTES
1 Sampling systems not completely in accordance with ISO 3081 or ISO 3082 are not always expected to
be biased. Therefore bias checking may be done when there is some disagreement about the importance of
some departure from the conditions of ISO 3081 and ISO 3082. If one party argues that the bias is likely to be
substantial under some particular set of conditions then bias testing should mostly be done when those
conditions apply.
2 The method for analysis of experimental data described here may also be applied:
a) for checking the bias of sample preparation of iron ores, having as reference the methods for sampling
preparation according to ISO 3082 and ISO 3083;
b) for checking a possibly significant difference in the results obtained from the samples of one lot
collected at different places, for example, a loading point and unloading point.
2 Normative references
The following Standards contain provisions which, through reference in the text, constitute provisions
of this International Standard. At the time of publication, the editions indicated were valid. All Standards
are subject to revision, and parties to agreements based on this International Standard are encouraged
to investigate the possibility of applying the most recent editions of the Standards indicated below.
Members of IEC and ISO maintain registers of currently valid International Standards.
1)
ISO 3081:1986 , Iron ores — Increment sampling — Manual method.
1)
ISO 3082:1987 , Iron ores — Increment sampling and sample preparation — Mechanical method.
1)
ISO 3083:1986 , Iron ores — Preparation of samples — Manual method.
ISO 3085:1996, Iron ores — Experimental methods for checking the precision of sampling.
ISO 11323:1996, Iron ores — Vocabulary.
3 Definitions
For the purposes of this International Standard, the definitions given in ISO 11323 apply.
———————
1)  To be revised and published as ISO 3082.
1

---------------------- Page: 7 ----------------------

SIST ISO 3086:2000
©
ISO
ISO 3086:1998(E)
4 Principle
The results obtained from the method to be checked (referred to as method B) are compared with the
results of a reference method (referred to as method A) which is considered to produce practically
unbiased results, from technical and empirical viewpoints.
In the event of there being no significant difference, in a statistical sense, between the results obtained
by method B and method A, method B may be adopted as a routine method. This difference is
assessed by comparing a 90 % confidence interval for the true average bias with the relevant bias,
d
(see 5.2).
5 General conditions
5.1  The number of lots to be tested shall be not less than ten. The number of further tests required
depends on the confidence interval for the true average bias, based on at least ten tests, and the value
of the relevant bias, d.
5.2  The relevant bias, d, which is considered large enough to justify the likely expense of reducing the
average bias, shall be decided beforehand. As a guide, d is likely to be less than s , the standard
SPM
deviation for sampling, sample preparation and measurement, determined according to ISO 3085.
NOTE —  If the experiment is aimed at checking the sample preparation only, the value of d is likely to be
less than s , determined according to ISO 3085.
PM
5.3  Quality characteristics such as total iron content, moisture content, size distribution and physical
properties may be used.
6 Sampling and sample preparation methods
6.1 Sampling
The reference method, method A, for checking the bias of sampling is a stopped-belt sampling method
according to ISO 3081.
Method A: take each increment from the full width and thickness of the ore stream on the stopped
conveyor at a specified place for a length of belt more than three times the nominal top size or
30 mm, whichever is the greater.
The method to be checked, method B, carried out according to ISO 3081 or ISO 3082, shall be
compared with method A for the same material.
Method B: sampling methods such as sampling from moving conveyors with a mechanical
sampler and sampling during the transfer to or from ships and wagons are examples of method B.
6.2 Sample preparation
Methods for making up a pair of gross samples, preparation of samples and testing shall be as given in
6.2.1 to 6.2.3.
6.2.1  Increments obtained from one lot, in accordance with method A and method B, are made up into
two gross samples, A and B.
6.2.2  The gross samples, A and B, are subjected, in the same manner, to sample preparation as
specified in ISO 3082 or ISO 3083 and tested as specified in the relevant International Standards
separately, and a pair of measurements obtained.
2

---------------------- Page: 8 ----------------------

SIST ISO 3086:2000
©
ISO
ISO 3086:1998(E)
6.2.3  The above procedure is performed on ten or more lots (see 5.1).
NOTES
1 When increments for method A and method B can be taken from closely adjacent portions of the ore, it is
recommended that sample preparation an
...