SIST EN ISO 16773-4:2009

SLOVENSKI STANDARD
01-september-2009
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Paints and varnishes - Electrochemical impedance spectroscopy (EIS) on high-
impedance coated specimens - Part 4: Examples of spectra of polymer-coated
specimens (ISO 16773-4:2009)
Beschichtungsstoffe - Elektrochemische Impedanzspektroskopie (EIS) von
beschichteten Proben mit hoher Impedanz - Teil 4: Beispiele für Spektren von
polymerbeschichteten Proben (ISO 16773-4:2009)
Peintures et vernis - Spectroscopie d'impédance électrochimique (SIE) sur des
éprouvettes revêtues de haute impédance - Partie 4: Exemples de spectres
d'éprouvettes revêtues de polymères (ISO 16773-4:2009)
Ta slovenski standard je istoveten z: EN ISO 16773-4:2009
ICS:
87.040 Barve in laki Paints and varnishes
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 16773-4
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2009
ICS 87.040
English Version
Paints and varnishes - Electrochemical impedance spectroscopy
(EIS) on high-impedance coated specimens - Part 4: Examples
of spectra of polymer-coated specimens (ISO 16773-4:2009)
Peintures et vernis - Spectroscopie d'impédance Beschichtungsstoffe - Elektrochemische
électrochimique (SIE) sur des éprouvettes revêtues de Impedanzspektroskopie (EIS) von beschichteten Proben
haute impédance - Partie 4: Exemples de spectres mit hoher Impedanz - Teil 4: Beispiele für Spektren von
d'éprouvettes revêtues de polymères (ISO 16773-4:2009) polymerbeschichteten Proben (ISO 16773-4:2009)
This European Standard was approved by CEN on 30 April 2009.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
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Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
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EUROPÄISCHES KOMITEE FÜR NORMUNG
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© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16773-4:2009: E
worldwide for CEN national Members.

Contents Page
Foreword .3

Foreword
This document (EN ISO 16773-4:2009) has been prepared by Technical Committee ISO/TC 35 "Paints and
varnishes" in collaboration with Technical Committee CEN/TC 139 “Paints and varnishes” the secretariat of
which is held by DIN.
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 November 2009, and conflicting national standards shall be withdrawn
at the latest by November 2009.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
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, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 16773-4:2009 has been approved by CEN as a EN ISO 16773-4:2009 without any
modification.
INTERNATIONAL ISO
STANDARD 16773-4
First edition
2009-05-01
Paints and varnishes — Electrochemical
impedance spectroscopy (EIS) on high-
impedance coated specimens —
Part 4:
Examples of spectra of polymer-coated
specimens
Peintures et vernis — Spectroscopie d'impédance électrochimique
(SIE) sur des éprouvettes revêtues de haute impédance —
Partie 4: Exemples de spectres d'éprouvettes revêtues de polymères

Reference number
ISO 16773-4:2009(E)
©
ISO 2009
ISO 16773-4:2009(E)
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ii © ISO 2009 – All rights reserved

ISO 16773-4:2009(E)
Contents Page
Foreword. iv
1 Scope .1
2 Theoretical background .1
Annex A (informative) Examples .5
Annex B (informative) Composition of concentrated artificial rain water.17
Bibliography .18

ISO 16773-4:2009(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 16773-4 was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee SC 9,
General test methods for paints and varnishes.
ISO 16773 consists of the following parts, under the general title Paints and varnishes — Electrochemical
impedance spectroscopy (EIS) on high-impedance coated specimens:
⎯ Part 1: Terms and definitions
⎯ Part 2: Collection of data
⎯ Part 3: Processing and analysis of data from dummy cells
⎯ Part 4: Examples of spectra of polymer-coated specimens

iv © ISO 2009 – All rights reserved

INTERNATIONAL STANDARD ISO 16773-4:2009(E)

Paints and varnishes — Electrochemical impedance
spectroscopy (EIS) on high-impedance coated specimens —
Part 4:
Examples of spectra of polymer-coated specimens
1 Scope
This part of ISO 16773 gives some typical examples of impedance spectra of high-impedance coated metal
samples. Some guidance on interpretation of such spectra is also given.
2 Theoretical background
2.1 Basic considerations
A basic introduction to electrochemical impedance spectroscopy, especially in connection with corrosion, is
given in ASTM G 106.
It is not intended to limit the interpretation of EIS measurements to the models given below. Other
interpretations may be valid. The choice of the proper model requires other experimental and theoretical
considerations to be taken into account.
2.2 Examples of models
2.2.1 Purely capacitive coating
A metal covered with an undamaged coating generally has a very high impedance. The equivalent circuit for
such a situation is shown in Figure 1.

Figure 1 — Equivalent circuit for a purely capacitive coating
The model includes a resistor representing the resistance R of the solution and, connected in series with it, a
capacitor representing the capacitance C of the coating.
In practice, the resistance of a perfect coating can often not be seen in the given frequency range. Any
deviation from the graph given in the Bode plot in Figure 2 indicates either a modified model or the input limits
of the impedance device (see Annex A of ISO 16773-2:2007).
ISO 16773-4:2009(E)
Key
X frequency f, in Hz
Y impedance Z, in Ω
X frequency f, in Hz
Y phase angle ϕ, in degrees
Figure 2 — Bode plot for a perfect coating
2.2.2 Randles equivalent circuit
The Randles equivalent circuit includes the resistance of the solution R , the capacitance of the coating C
S C
and the ohmic resistance of the coating R , as shown in Figure 3.
C
Figure 3 — Randles equivalent circuit
2 © ISO 2009 – All rights reserved

ISO 16773-4:2009(E)
The Bode plot for a Randles equivalent circuit is shown in Figure 4.

Key
X logf (f in Hz)
Y log|Z| (Z in Ω)
Y |ϕ| (degrees)
1 phase angle ϕ
2 impedance Z
Figure 4 — Bode plot for a Randles equivalent circuit
2.2.3 Extended Randles equivalent circuit
Quite often, fitting experimental data to the model shown in Figure 3 results in systematic errors. In such
cases, the literature shows that it is possible to use the model shown in Figure 5 to obtain a better fit.

Figure 5 — Extended Randles equivalent circuit
NOTE This model is not necessarily the most appropriate and other models are not excluded.
In the case of high-impedance coatings, the charge-transfer resistance R and double-layer capacitance C in
ct dl
the extended Randles circuit correspond to properties of the coating rather than to corrosion processes in the
underlying metal.
The Bode plot shown in Figure 6 clearly shows the additional contribution of these two added elements.
Again, the Bode plot does not go high enough in frequency to measure the solution resistance. In practice this
is not a problem, because the solution resistance is a property of the test solution and the test cell geometry,
not a property of the coating.
ISO 16773-4:2009(E)
Key
X logf (f in Hz)
Y log|Z| (Z in Ω)
Y |ϕ| (degrees)
1 phase angle ϕ
2 impedance Z
Figure 6 — Bode plot for an extended Randles equivalent circuit
4 © ISO 2009 – All rights reserved

ISO 16773-4:2009(E)
Annex A
(informative)
Examples
A.1 General
This annex contains a collection of spectra obtained from materials described briefly in the relevant clause.
The examples were obtained from various laboratories using a range of different equipment and materials.
This collection of spectra is not intended to imply that all the materials mentioned necessarily give spectra
similar to those shown or that the spectra given here are free of experimental errors. The collection does not
represent the complete range of coating materials.
ISO 16773-4:2009(E)
A.2 Example 1
This example shows how a smaller than usual thickness of
...