ISO 13909-4:2016

INTERNATIONAL ISO
STANDARD 13909-4
Second edition
2016-07-01
Hard coal and coke — Mechanical
sampling —
Part 4:
Coal — Preparation of test samples
Houille et coke — Échantillonnage mécanique —
Partie 4: Charbon — Préparation des échantillons pour essai
Reference number
©
ISO 2016
© ISO 2016, Published in Switzerland
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ii © ISO 2016 – All rights reserved

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Precision of sample preparation . 1
5 Constitution of a sample . 2
5.1 Introduction . 2
5.2 Combination of increments . 2
5.2.1 Time-basis sampling . . 2
5.2.2 Mass-basis sampling . 2
5.3 Combination of samples . 3
6 Division . 3
6.1 General . 3
6.2 Mechanical methods .10
6.2.1 General.10
6.2.2 Mass of cut .10
6.2.3 Interval between cuts .10
6.2.4 Division of individual increments .10
6.2.5 Division of samples .13
6.3 Manual methods .14
6.3.1 Riffle method .14
6.3.2 Flattened-heap method .15
6.3.3 Strip-mixing and splitting method .17
7 Reduction .19
7.1 General .19
7.2 Reduction mills .19
8 Mixing.19
9 Air-drying .19
10 Preparation of samples for specific tests .20
10.1 Types of test samples .20
10.2 Preparation of samples for determination of total moisture only .20
10.2.1 General.20
10.2.2 Storage .22
10.2.3 Sample reduction.22
10.2.4 Sample division .23
10.3 Preparation of samples for general analysis only .23
10.3.1 General.23
10.3.2 Air-drying .23
10.3.3 Reduction and division .23
10.4 Common samples .24
10.4.1 General.24
10.4.2 Extraction of moisture sample by mechanical division.25
10.4.3 Extraction of moisture sample by manual method .25
10.5 Preparation of size-analysis sample .26
10.6 Preparation of samples for other tests .27
11 Reserve sample .28
12 Design of equipment for preparation .28
12.1 Dividers .28
12.2 Design of cutters for falling-stream dividers .28
12.2.1 General.28
12.2.2 Cutter velocity .29
12.3 Preparation systems .29
12.3.1 General.29
12.3.2 Design criteria .29
12.3.3 Abnormal operation .30
12.4 Provision for checking for precision .30
12.5 Provision for testing for bias .30
Bibliography .31
iv © ISO 2016 – All rights reserved

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
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electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT), see the following URL: Foreword — Supplementary information.
The committee responsible for this document is ISO/TC 27, Solid mineral fuels, Subcommittee SC 4,
Sampling.
This second edition cancels and replaces the first edition (ISO 13909-4:2001), which has been
technically revised.
ISO 13909 consists of the following parts, under the general title Hard coal and coke — Mechanical
sampling:
— Part 1: General introduction
— Part 2: Coal — Sampling from moving streams
— Part 3: Coal — Sampling from stationary lots
— Part 4: Coal — Preparation of t
...