oSIST prEN ISO 287:2026

SLOVENSKI STANDARD
01-julij-2026
Papir, karton in lepenka - Ugotavljanje vlage v vzorcu pošiljke - Metoda sušenja v
sušilniku (ISO/DIS 287:2026)
Paper and board - Determination of moisture content of a lot - Oven-drying method
(ISO/DIS 287:2026)
Papier und Pappe - Bestimmung des Feuchtegehaltes eines Lieferpostens -
Wärmeschrankverfahren (ISO/DIS 287:2026)
Papier et carton - Détermination de la teneur en humidité d'un lot - Méthode par séchage
à l'étuve (ISO/DIS 287:2026)
Ta slovenski standard je istoveten z: prEN ISO 287
ICS:
85.060 Papir, karton in lepenka Paper and board
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 287
ISO/TC 6/SC 2
Paper and board — Determination
Secretariat: SIS
of moisture content of a lot — Oven-
Voting begins on:
drying method
2026-04-16
Papier et carton — Détermination de la teneur en humidité d'un
Voting terminates on:
lot — Méthode par séchage à l'étuve
2026-07-09
ICS: 85.060
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
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STANDARDS MAY ON OCCASION HAVE TO
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NATIONAL REGULATIONS.
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NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 287:2026(en)
DRAFT
ISO/DIS 287:2026(en)
International
Standard
ISO/DIS 287
ISO/TC 6/SC 2
Paper and board — Determination
Secretariat: SIS
of moisture content of a lot — Oven-
Voting begins on:
drying method
Papier et carton — Détermination de la teneur en humidité d'un
Voting terminates on:
lot — Méthode par séchage à l'étuve
ICS: 85.060
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
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BE CONSIDERED IN THE LIGHT OF THEIR
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Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 287:2026(en)
ii
ISO/DIS 287:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Preparation of containers . 2
7 Sampling . 2
8 Selection, preparation and weighing of test pieces . 3
8.1 General .3
8.2 If the unit is a package that can be and may be unwrapped, or is in an unwrapped form .3
8.2.1 When the unit is not subdivided and not a reel .3
8.2.2 When the unit is composed of elements .4
8.2.3 When the unit is a reel .5
8.3 When the unit is a package that cannot or should not be completely unwrapped .5
8.3.1 Average moisture content for samples with known machine direction.5
8.3.2 Average moisture content for samples with unknown machine direction .5
8.3.3 Variations in moisture content of sheets or across the reel .6
9 Procedure . 6
9.1 Initial drying and weighing .6
9.2 Drying and weighing to constant mass .6
9.3 Variation check .6
10 Calculation and expression of results . 7
10.1 Calculation .7
10.2 Expression of results . .7
11 Test report . 7
Annex A (informative) Precision data . 9
Bibliography .10

iii
ISO/DIS 287:2026(en)
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.
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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
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this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 6, Pulp and paper, Subcommittee SC 2, methods
and quality specifications for paper and board.
This fifth edition cancels and replaces the fourth edition (ISO 287:2017) which has been technically revised.
The main changes are as follows:
— update of the normative references;
— update of the definition of the term „constant mass”;
— addition of requirements for the apparatus “desiccator” and new apparatus “desiccant”;
— revision regarding the removal of subdivisions relating to different grammages in section 8.2;
2 2
— revision regarding the grammage, from 25 g/m to 200 g/m ;
— addition of sample mass for low grammage samples in 8.2 and 8.3;
— addition of new 9.3 “variation check”;
— addition of provision for absolute difference between the results of two parallel tests;
— update of the test report regarding the desiccator.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
ISO/DIS 287:2026(en)
Introduction
The determination of dry matter content and moisture content are carried out for different purposes.
ISO 638 is used in cases where the dry matter content is needed to calculate the result of chemical analysis
or physical testing and when the determination of the moisture content of a sample, rather than a lot, is
required. As an example, the dry matter content of the sample is needed to express the content of elements,
such as cadmium and manganese, in relation to the oven-dry mass of the sample.
This document is used for the purpose of determining the average moisture content and the variation in
moisture content (maximum and minimum values) of a lot. In the paper and board trade, the moisture
content is important since it influences converting processes, such as printing and copying. The moisture
content also has an influence on curl and dimensional stability.

v
DRAFT International Standard ISO/DIS 287:2026(en)
Paper and board — Determination of moisture content of a
lot — Oven-drying method
1 Scope
This document specifies an oven-drying method for the determination of the moisture content of a lot
of paper and board. The procedure in Clause 8, describing how the test pieces are drawn from the lot, is
performed at the time of sampling.
This document is applicable to every type of lot of paper and board, including corrugated board and solid
board, provided that the paper or board does not contain any substances, other than water, that are volatile
at the temperature specified in this document.
NOTE For determination of the dry matter content of a sample of paper or board, e.g. for calculation of the dry
[1]
mass of the sample, ISO 638 can be used.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 186, Paper and board — Sampling to determine average quality
ISO 13130, Laboratory glassware — Desiccators
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
moisture content
w
HO
content of water in paper or board, i.e. the ratio of the loss of mass of a test piece, when dried under specified
conditions, to its mass at the time of sampling
Note 1 to entry: The moisture content is normally expressed as a percentage mass fraction.
3.2
constant mass
mass of the test piece determined at the equilibrium condition after drying until the difference between
two successive dryings and weighings, separated in time by at least half the initial drying period, does not
exceed 0,1 % mass fraction of the test piece before drying
[SOURCE: EN ISO 638-1:2022, 3.2]

ISO/DIS 287:2026(en)
4 Principle
At the time of sampling, test pieces taken from a lot are weighed and the test pieces are weighed again after
drying to constant mass. From the mass of a test piece before and after drying, the moisture content is
calculated.
5 Apparatus
5.1 Balance, having an accuracy of 0,05 % of the mass to be weighed, or better.
5.2 Containers, for the transport and weighing of test pieces, which shall be water-vapour proof and
made from a lightweight material that is not subject to change under the conditions of test.
5.3 Oven, capable of maintaining the air temperature at (105 ± 2) °C and suitably ventilated to maintain a
uniform temperature in the usable volume while extracting the moisture driven off the test pieces.
5.4 Desiccator, filled with desiccant to such an extent that there is at least a 10 mm gap be
...