SIST EN ISO 11844-2:2020
(Main)Corrosion of metals and alloys - Classification of low corrosivity of indoor atmospheres - Part 2: Determination of corrosion attack in indoor atmospheres (ISO 11844-2:2020)
Corrosion of metals and alloys - Classification of low corrosivity of indoor atmospheres - Part 2: Determination of corrosion attack in indoor atmospheres (ISO 11844-2:2020)
This document specifies methods for determining corrosion rates with standard specimens of metals
in indoor atmospheres with low corrosivity. For this direct method of evaluation corrosivity, different
sensitive methods can be applied using standard specimens of the following metals: copper, silver, zinc,
steel and lead. The values obtained from the measurements are used as classification criteria for the
determination of indoor atmospheric corrosivity.
Korrosion von Metallen und Legierungen - Einteilung der Korrosivität in Räumen mit geringer Korrosivität - Teil 2: Bestimmung der korrosiven Belastung in Räumen (ISO 11844-2:2020)
Dieses Dokument legt Verfahren zur Bestimmung von Korrosionsgeschwindigkeiten an Metall-Standard¬proben in Innenräumen mit geringer Korrosivität fest. Für diese direkte Bewertung der Korrosivität können Methoden mit unterschiedlicher Empfindlichkeit angewendet werden, bei denen metallene Standardproben aus Kupfer, Silber, Zink, Stahl und Blei verwendet werden. Die bei den Messungen bestimmten Werte werden als Einteilungskriterien zur Bestimmung der atmosphärischen Korrosivität in Innenräumen ange¬wendet.
Corrosion des métaux et alliages - Classification de la corrosivité faible des atmosphères d'intérieur - Partie 2: Détermination de l'attaque par corrosion dans les atmosphères d'intérieur (ISO 11844-2:2020)
Le présent document spécifie des méthodes de détermination de la vitesse de corrosion avec des éprouvettes normalisées de métaux dans des atmosphères d'intérieur à faible corrosivité. Pour cette évaluation directe de la corrosivité, différentes méthodes sensibles peuvent être appliquées à des éprouvettes normalisées des métaux suivants: cuivre, argent, zinc, acier et plomb. Les valeurs obtenues par mesurage servent de critères de classification pour la détermination de la corrosivité des atmosphères d'intérieur.
Korozija kovin in zlitin - Klasifikacija notranjih atmosfer z nizko korozivnostjo - 2. del: Ugotavljanje napada korozije v zaprtih prostorih (ISO 11844-2:2020)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 11844-2:2020
01-september-2020
Nadomešča:
SIST EN ISO 11844-2:2008
Korozija kovin in zlitin - Klasifikacija notranjih atmosfer z nizko korozivnostjo - 2.
del: Ugotavljanje napada korozije v zaprtih prostorih (ISO 11844-2:2020)
Corrosion of metals and alloys - Classification of low corrosivity of indoor atmospheres -
Part 2: Determination of corrosion attack in indoor atmospheres (ISO 11844-2:2020)
Korrosion von Metallen und Legierungen - Einteilung der Korrosivität in Räumen mit
geringer Korrosivität - Teil 2: Bestimmung der korrosiven Belastung in Räumen (ISO
11844-2:2020)
Corrosion des métaux et alliages - Classification de la corrosivité faible des atmosphères
d'intérieur - Partie 2: Détermination de l'attaque par corrosion dans les atmosphères
d'intérieur (ISO 11844-2:2020)
Ta slovenski standard je istoveten z: EN ISO 11844-2:2020
ICS:
77.060 Korozija kovin Corrosion of metals
SIST EN ISO 11844-2:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 11844-2:2020
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SIST EN ISO 11844-2:2020
EN ISO 11844-2
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2020
EUROPÄISCHE NORM
ICS 77.060 Supersedes EN ISO 11844-2:2008
English Version
Corrosion of metals and alloys - Classification of low
corrosivity of indoor atmospheres - Part 2: Determination
of corrosion attack in indoor atmospheres (ISO 11844-
2:2020)
Corrosion des métaux et alliages - Classification de la Korrosion von Metallen und Legierungen - Einteilung
corrosivité faible des atmosphères d'intérieur - Partie der Korrosivität in Räumen mit geringer Korrosivität -
2: Détermination de l'attaque par corrosion dans les Teil 2: Bestimmung der korrosiven Belastung in
atmosphères d'intérieur (ISO 11844-2:2020) Räumen (ISO 11844-2:2020)
This European Standard was approved by CEN on 26 April 2020.
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-CENELEC 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-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11844-2:2020 E
worldwide for CEN national Members.
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SIST EN ISO 11844-2:2020
EN ISO 11844-2:2020 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO 11844-2:2020
EN ISO 11844-2:2020 (E)
European foreword
This document (EN ISO 11844-2:2020) has been prepared by Technical Committee ISO/TC 156
"Corrosion of metals and alloys" in collaboration with Technical Committee CEN/TC 262 “Metallic and
other inorganic coatings, including for corrosion protection and corrosion testing of metals and alloys”
the secretariat of which is held by BSI.
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 December 2020, and conflicting national standards
shall be withdrawn at the latest by December 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 11844-2:2008.
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,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 11844-2:2020 has been approved by CEN as EN ISO 11844-2:2020 without any
modification.
3
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SIST EN ISO 11844-2:2020
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SIST EN ISO 11844-2:2020
INTERNATIONAL ISO
STANDARD 11844-2
Second edition
2020-05
Corrosion of metals and alloys —
Classification of low corrosivity of
indoor atmospheres —
Part 2:
Determination of corrosion attack in
indoor atmospheres
Corrosion des métaux et alliages — Classification de la corrosivité
faible des atmosphères d'intérieur —
Partie 2: Détermination de l'attaque par corrosion dans les
atmosphères d'intérieur
Reference number
ISO 11844-2:2020(E)
©
ISO 2020
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SIST EN ISO 11844-2:2020
ISO 11844-2:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
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SIST EN ISO 11844-2:2020
ISO 11844-2:2020(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Methods . 1
Annex A (informative) Determination of corrosion rate by mass change measurement .4
Annex B (informative) Determination of corrosion rate by electrolytic cathodic reduction .8
Annex C (informative) Determination of corrosion rate by resistance measurements .10
Annex D (informative) Determination of corrosion rate by quartz crystal micro-balance
methodology .12
Bibliography .15
© ISO 2020 – All rights reserved iii
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SIST EN ISO 11844-2:2020
ISO 11844-2:2020(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.
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 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 156, Corrosion of metals and alloys, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/
TC 262, Metallic and other inorganic coatings, including for corrosion protection and corrosion testing of
metals and alloys, in accordance with the Agreement on technical cooperation between ISO and CEN
(Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 11844-2:2005), which has been
technically revised. The main changes compared with the previous edition are as follows:
— lead has been included as a standard specimen with high sensitivity to vapour organic acids;
— Annex D has been added.
A list of all parts in the ISO 11844 series can be found on the ISO website.
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 2020 – All rights reserved
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SIST EN ISO 11844-2:2020
ISO 11844-2:2020(E)
Introduction
This document describes standard specimens, exposure and evaluation for the derivation of indoor
corrosivity categories.
The determination of the corrosion attack is, at the present state of knowledge, the most reliable
and, usually, also an economical way for evaluating corrosivity, taking into account all the main local
environmental influences.
© ISO 2020 – All rights reserved v
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SIST EN ISO 11844-2:2020
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SIST EN ISO 11844-2:2020
INTERNATIONAL STANDARD ISO 11844-2:2020(E)
Corrosion of metals and alloys — Classification of low
corrosivity of indoor atmospheres —
Part 2:
Determination of corrosion attack in indoor atmospheres
1 Scope
This document specifies methods for determining corrosion rates with standard specimens of metals
in indoor atmospheres with low corrosivity. For this direct method of evaluation corrosivity, different
sensitive methods can be applied using standard specimens of the following metals: copper, silver, zinc,
steel and lead. The values obtained from the measurements are used as classification criteria for the
determination of indoor atmospheric corrosivity.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Principle
The corrosivity of the indoor location (e.g. control rooms, electric boxes, storage rooms, during
transportation, in museums) is determined from the corrosion rate calculated from the mass change
or resistance change per unit area of standard specimens of metals after exposure for a certain time
period. Different materials are sensitive to different environmental parameters or their combinations.
5 Methods
The following methods, described in Annexes A and B, are available for the evaluation of the
corrosion attack:
— determination of corrosion rate by mass change measurements (see Annex A);
— determination of corrosion rate by electrolytic cathodic reduction (see Annex B).
The methods described in Annexes C and D are suitable for continuous or periodic monitoring of the
corrosion attack:
— determination of corrosion rate by resistance measurements (see Annex C);
— determination of corrosion rate by quartz crystal micro-balance methodology (see Annex D).
© ISO 2020 – All rights reserved 1
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SIST EN ISO 11844-2:2020
ISO 11844-2:2020(E)
Special features of the methods, such as sensitivity, possibility for continuous or periodic assessment of
corrosion attack, available space, etc., should be considered when choosing the most suitable methods.
Examples of suitable racks for exposure of specimens are given in Figures 1 and 2.
Dimensions in millimetres
Key
1 specimens
2 support ∅ approximately 15
Figure 1 — Example of exposure racks for the sheltered exposure of specimens
2 © ISO 2020 – All rights reserved
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SIST EN ISO 11844-2:2020
ISO 11844-2:2020(E)
Dimensions in millimetres
Key
1 specimens 4 open air flow
2 distance pins 5 plastic screws
3 plastic plates
Figure 2 — A mounting plate for the unsheltered exposure of specimens
© ISO 2020 – All rights reserved 3
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SIST EN ISO 11844-2:2020
ISO 11844-2:2020(E)
Annex A
(informative)
Determination of corrosion rate by mass change measurement
A.1 Principle
Mass increase measurements can be performed on all metals and comparatively large surfaces can be
evaluated. The technique is relatively easy to operate.
The mass loss determination gives a best estimate of the corrosion effect. The method is not yet
applicable to all metals. Both mass increase and mass loss determination using an ultra-micro-balance
2
has a precision of about ±10 mg/m with the method described below.
Due to the difficulty of distinguishing corrosion effects from other surface-related phenomena, such as
sorption and contamination by particulate matter, the specimens should preferably be exposed under
shelter.
A.2 Specimens
It is preferable to use rectangular specimens in the form of flat sheets, as they can be readily weighed.
A convenient specimen size is 10 mm × 50 mm. Specimens may be larger provided that they can be
accurately weighed. The specimen thickness may preferably be 0,5 mm.
The materials used to prepare the specimens are of following quality:
Silver: 99,98 % min.
Copper: 99,85 % min.
Zinc: 99,45 % min.
Carbon steel: CR 1, max. 0,15 % C, max. 0,04 % P, max. 0,05 % S, max. 0,6 % Mn
Lead: 99,97 % min.
The specimens should, before weighing, be prepared as follows.
a) A hole with the diameter 4 mm is cut at the upper side of the specimen.
b) Abrading:
1) silver and copper with silicon carbide paper to 1 200 P (600 grit);
2) zinc, carbon steel and lead to 500 P (320 grit).
To avoid risk of contamination, an abrading paper shall not be used for polishing specimens of
different metals.
c) Cleaning in de-ionised water.
d) Degreasing in ethanol in an ultrasonic bath for 5 min.
e) Drying.
4 © ISO 2020 – All rights reserved
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SIST EN ISO 11844-2:2020
ISO 11844-2:2020(E)
f) Storing in plastic tubes with a hole in the top. The plastic tubes are placed in a desiccator or sealed
into plastic bags with desiccant before and after the weighing and the exposure.
After the final surface cleaning before exposure, it is important that limited handling occurs. Before and
after weighing, the specimens are placed in tubes and are only handled with a clean pair of tweezers. To
avoid marking on the specimens, the identity of the specimens may preferably be marked on the tubes.
A.3 Exposure
The specimens shall be exposed vertically, either with or without a shelter against settling particles (see
Figure 1). The specimens shall be mounted between plastic plates or racks to permit free air circulation.
A distance of a minimum of 10 mm between the surfaces and/or the surface and the mounting plate
is recommended. The plastic racks or mounting plates are placed at a site with free air circulation,
preferably at a height of 1 m above the floor. The exposure should be performed in an area with airflow
rates characteristic of the site.
A map of specimen identity on the plastic rack, exposure date and location of the exposure rack should
be established. The type of exposure, with or without a shelter, should be noted.
The test specimens (at least three) should be exposed preferably for one year, but at least for six months.
A.4 Mass increase
The specimens shall be weighed on a micro-balance, with an accuracy of ±0,1 mg. Each test specimen
is weighed twice in relation to a reference balance standard of stainless steel having a similar mass to
the specimen. The difference between the first mass o
...
SLOVENSKI STANDARD
oSIST prEN ISO 11844-2:2019
01-januar-2019
Korozija kovin in zlitin - Klasifikacija notranjih atmosfer z nizko korozivnostjo - 2.
del: Ugotavljanje napada korozije v zaprtih prostorih (ISO/DIS 11844-2:2018)
Corrosion of metals and alloys - Classification of low corrosivity of indoor atmospheres -
Part 2: Determination of corrosion attack in indoor atmospheres (ISO/DIS 11844-2:2018)
Korrosion von Metallen und Legierungen - Einteilung der Korrosivität in Räumen mit
geringer Korrosivität - Teil 2: Bestimmung der korrosiven Belastung in Räumen (ISO/DIS
11844-2:2018)
Corrosion des métaux et alliages - Classification de la corrosivité faible des atmosphères
d'intérieur - Partie 2: Détermination de l'attaque par corrosion dans les atmosphères
d'intérieur (ISO/DIS 11844-2:2018)
Ta slovenski standard je istoveten z: prEN ISO 11844-2
ICS:
77.060 Korozija kovin Corrosion of metals
oSIST prEN ISO 11844-2:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
oSIST prEN ISO 11844-2:2019
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oSIST prEN ISO 11844-2:2019
DRAFT INTERNATIONAL STANDARD
ISO/DIS 11844-2
ISO/TC 156 Secretariat: SAC
Voting begins on: Voting terminates on:
2018-11-12 2019-02-04
Corrosion of metals and alloys — Classification of low
corrosivity of indoor atmospheres —
Part 2:
Determination of corrosion attack in indoor atmospheres
Corrosion des métaux et alliages — Classification de la corrosivité faible des atmosphères d'intérieur —
Partie 2: Détermination de l'attaque par corrosion dans les atmosphères d'intérieur
ICS: 77.060
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 11844-2:2018(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2018
---------------------- Page: 3 ----------------------
oSIST prEN ISO 11844-2:2019
ISO/DIS 11844-2:2018(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved
---------------------- Page: 4 ----------------------
oSIST prEN ISO 11844-2:2019
ISO/DIS 11844-2:2018(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Principle . 1
4 Methods . 1
Annex A (normative) Determination of corrosion rate by mass change measurement .3
Annex B (normative) Determination of corrosion rate by electrolytic cathodic reduction .7
Annex C (informative) Determination of corrosion rate by resistance measurements .9
Annex D (informative) Determination of corrosion rate by quartz crystal micro-balance
methodology .11
Bibliography .14
© ISO 2018 – All rights reserved iii
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oSIST prEN ISO 11844-2:2019
ISO/DIS 11844-2:2018(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.
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 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.
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.
ISO 11844-2 was prepared by Technical Committee ISO/TC 156, Corrosion of metals and alloys.
ISO 11844 consists of the following parts, under the general title Corrosion of metals and alloys —
Classification of low corrosivity of indoor atmospheres:
— Part 1: Determination and estimation of indoor corrosivity;
— Part 2: Determination of corrosion attack in indoor atmospheres;
— Part 3: Measurement of environmental parameters affecting indoor corrosivity.
This second edition cancels and replaces the first edition (ISO 11844-2:2006), which has been
technically revised.
iv © ISO 2018 – All rights reserved
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oSIST prEN ISO 11844-2:2019
ISO/DIS 11844-2:2018(E)
Introduction
ISO 11844 – Part 2 describes standard specimens, its exposure and evaluation for the derivation of the
indoor corrosivity categories.
The determination of the corrosion attack is at the present state of knowledge the most reliable
and usually also an economical way for evaluation of corrosivity taking into account all main local
environmental influences.
© ISO 2018 – All rights reserved v
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oSIST prEN ISO 11844-2:2019
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oSIST prEN ISO 11844-2:2019
DRAFT INTERNATIONAL STANDARD ISO/DIS 11844-2:2018(E)
Corrosion of metals and alloys — Classification of low
corrosivity of indoor atmospheres —
Part 2:
Determination of corrosion attack in indoor atmospheres
1 Scope
This International Standard specifies methods for determination of corrosion rate with standard
specimens of metals in indoor atmospheres with low corrosivity. For this direct method of evaluation
corrosivity different sensitive methods can be applied using standard specimens of the following
metals: copper, silver, zinc steel and lead. The values obtained from the measurements are used as
classification criteria for the determination of indoor atmospheric corrosivity.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For datedreferences, only the edition cited applies. For undated references, the latest edition of the
referenced document (including any amendments) applies.
IEC 60654-4:1987, Operating conditions for industrial-process measurement and control equipment —
Part 4: Corrosive and erosive influences
ANSI/ISA-S71.04:1985, Environmental conditions for Process, Measurement and Control Systems: Airborne
Contaminants
3 Principle
The corrosivity of the indoor location, e.g. control rooms, electric boxes, storage rooms, during
transportation, in museums, etc., is determined from the corrosion rate calculated from the mass
change or resistance change per unit area of standard specimens of metals after exposure for a
certain time period. Different materials are sensitive to different environmental parameters or their
combinations.
4 Methods
The following methods described in Annexes A and B are available for evaluation of the corrosion attack:
— Determination of corrosion rate by mass change measurements (Annex A);
— Determination of corrosion rate by electrolytic cathodic reduction (Annex B).
The method described in the informative Annexes C and D are suitable for continuous or periodic
monitoring of the corrosion attack:
— Determination of corrosion rate by resistance measurements (Annex C);
— Determination of corrosion rate by quartz crystal micro-balance methodology (Annex D).
Special features of the methods, such as sensitivity, possibility for continuous or periodic assessment of
corrosion attack, available space, etc., should be considered when choosing the most suitable methods.
Examples of suitable racks for exposure of specimens are given in Figures 1 and 2.
© ISO 2018 – All rights reserved 1
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oSIST prEN ISO 11844-2:2019
ISO/DIS 11844-2:2018(E)
Key
1 specimens
2 support ∅ ~ 15
Figure 1 — Examples of exposure racks for sheltered exposure of specimens
Key
1 Specimens
2 Distance pins
3 Plastic plates
4 Open air flow
5 Distance pins
6 Plastic screws
Figure 2 — A mounting plate for unsheltered exposure of specimens
2 © ISO 2018 – All rights reserved
---------------------- Page: 10 ----------------------
oSIST prEN ISO 11844-2:2019
ISO/DIS 11844-2:2018(E)
Annex A
(normative)
Determination of corrosion rate by mass change measurement
A.1 Principle
Mass increase measurements can be performed on all metals and comparatively large surfaces can be
evaluated. The technique is relatively easy to operate.
The mass loss determination gives a best estimate of the corrosion effect. The method is not yet
applicable to all metals. Both mass increase and mass loss determination using an ultramicro-balance
2
has a precision of about ± 10 mg/m with the method described below.
Due to the difficulty of distinguishing corrosion effects from other surface-related phenomena, such as
sorption and contamination by particulate matter, the specimens should preferably be exposed under
shelter.
A.2 Specimens
It is preferable to use rectangular specimens in the form of flat sheets, as they can be readily weighed.
A convenient specimen size is 10 mm ⋅ 50 mm. Specimens may be larger provided that they can be
accurately weighed. The specimen thickness may preferably be 0,5 mm.
The materials used to prepare the specimens are of following quality,
Silver: 99,98 % min.
Copper: 99,85 % min.
Zinc: 99,45 % min.
Carbon steel: CR 1, max 0,15 % C, max 0,04 % P, max 0,05 % S, max 0,6 % Mn
Lead: 99,97 % min.
The specimens should, before weighing, be prepared as follows:
a) A hole with the diameter 4 mm is cut at the upper side of the specimen.
b) Abrading:
— Silver and copper with silicon carbide paper to 1 200 P (600 grit),
— Zinc, carbon steel and lead to 500 P (320 grit).
NOTE To avoid risk of contamination an abrading paper must not be used for polishing of specimens of
different metals.
c) Cleaning in de-ionised water.
d) Degreasing in ethanol in an ultrasonic bath for 5 minutes.
e) Drying.
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oSIST prEN ISO 11844-2:2019
ISO/DIS 11844-2:2018(E)
f) Store in plastic tubes with a hole in the top. The plastic tubes are placed in a desiccator or sealed
into plastic bags with desiccant before and after the weighing and the exposure.
After final surface cleaning before exposure, it is important that limited handling occurs. Before and
after weighing, the specimens are placed in tubes and are only handled with a clean pair of tweezers. To
avoid marking on the specimens, the identity of the specimens may preferably be marked on the tubes.
A.3 Exposure
The specimens shall be exposed vertically, either with or without a shelter against settling particles (see
Figure 1). The specimens shall be mounted between plastic plates or racks to permit free air circulation.
A distance of a minimum of 10 mm between the surfaces and/or the surface and the mounting plate
is recommended. The plastic racks or mounting plates are placed at a site with free air circulation,
preferably at a height of 1 m above the floor. The exposure should be performed in an area with airflow
rates characteristic of the site.
A map of specimen identity on the plastic rack, exposure date and location of the exposure rack should
be established. The type of exposure, with or without a shelter, should be noted.
The test specimens (at least three) should be exposed preferably for one year but at least for six months.
A.4 Mass increase
The specimens shall be weighed on a micro-balance, with an accuracy of ±0,1 mg. Each test specimen
is weighed twice in relation to a reference balance standard of stainless steel having a similar mass to
the specimen. The difference between the first mass of the test specimen m1 and the reference balance
standard m is calculated as (m − m ), and the difference between the second masses (m − m )
r,1 r,1 1 r,2 2
is calculated in the same way. The mass of the test specimen is calculated in relation to the reference
specimen as the average of the differences (m):
()mm−+()mm−
r,11 r,22
m= (1)
2
where
m is the mass of the test specimen in relation to the reference balance standard, in mg;
m is the mass of the test specimen at first weighing, in mg;
1
m is the mass of the test specimen at second weighing, in mg;
2
m is the mass of the reference balance standard at first weighing, in mg;
r,1
m is the mass of the reference balance standard at second weighing, in mg.
r,2
The same weighing procedure is performed both before and after the exposure of the specimens. After
the exposure, the specimens should be carefully blown with oil-free compressed air or nitrogen to
remove dust before the weighing.
The rate of mass increase for each metal is given by the following equation:
mm−
ae be
r = (2)
mi
At⋅
where
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oSIST prEN ISO 11844-2:2019
ISO/DIS 11844-2:2018(E)
2
r is the rate of mass increase in mg/m ⋅a;
mi
m is the mass of the test specimen in relation to the reference balance standard after expo-
ae
sure, in mg;
m is the mass of the test specimen in relation to the reference balance standard before expo-
be
sure, in mg;
2
A is the surface area including both sides and edges, in m ;
t is the exposure time; in years (with the unit symbol a).
A.5 Mass loss
The specimens shall be weighed on a micro-balance, with an accuracy of ±0,1 mg. The specimens
are weighed in relation to a reference balance standard of stainless steel before exposure, see the
description in Clause 3. After the exposure, the specimens are pickled in the following solutions:
Silver: 750 ml hydrochloric acid (HCl, density = 1,18 g/ml). Distilled water to make up to
1000 ml
Copper: aqueous amidosulfonic acid (sulfamic acid)
...
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