EN ISO 16773-2:2007

SLOVENSKI STANDARD
01-julij-2007
%DUYHLQODNL(OHNWURNHPLMVNDLPSHGDQþQDVSHNWURVNRSLMD(,6Y]RUFHY]YLVRNR
LPSHGDQFRGHO=ELUDQMHSRGDWNRY,62
Paints and varnishes - Electrochemical impedance spectroscopy (EIS) on high-
impedance coated specimens - Part 2: Collection of data (ISO 16773-2:2007)
Beschichtungsstoffe - Elektrochemische Impedanzspektroskopie (EIS) von
beschichteten Proben mit hoher Impedanz - Teil 2: Datenerfassung (ISO 16773-2:2007)
Peintures et vernis - Spectroscopie d'impédance électrochimique (SIE) sur des
éprouvettes revetues de haute impédance - Partie 2: Recueil des données (ISO 16773-
2:2007)
Ta slovenski standard je istoveten z: EN ISO 16773-2:2007
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 16773-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2007
ICS 87.040
English Version
Paints and varnishes - Electrochemical impedance spectroscopy
(EIS) on high-impedance coated specimens - Part 2: Collection
of data (ISO 16773-2:2007)
Peintures et vernis - Spectroscopie d'impédance Beschichtungsstoffe - Elektrochemische
électrochimique (SIE) sur des éprouvettes revêtues de Impedanzspektroskopie (EIS) von beschichteten Proben
haute impédance - Partie 2: Recueil des données (ISO mit hoher Impedanz - Teil 2: Datenerfassung (ISO 16773-
16773-2:2007) 2:2007)
This European Standard was approved by CEN on 7 January 2007.
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,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16773-2:2007: E
worldwide for CEN national Members.

Foreword
This document (EN ISO 16773-2:2007) 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 October 2007, and conflicting national
standards shall be withdrawn at the latest by October 2007.

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 United
Kingdom.
Endorsement notice
The text of ISO 16773-2:2007 has been approved by CEN as EN ISO 16773-2:2007 without any
modifications.
INTERNATIONAL ISO
STANDARD 16773-2
First edition
2007-04-01
Paints and varnishes — Electrochemical
impedance spectroscopy (EIS) on high-
impedance coated specimens —
Part 2:
Collection of data
Peintures et vernis — Spectroscopie d'impédance électrochimique
(SIE) sur des éprouvettes revêtues de haute impédance —
Partie 2: Recueil des données
Reference number
ISO 16773-2:2007(E)
©
ISO 2007
ISO 16773-2:2007(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2007
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 either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2007 – All rights reserved

ISO 16773-2:2007(E)
Contents Page
Foreword. iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Principle. 1
5 Electrochemical cell . 2
6 Procedure . 3
7 Instrumental parameters. 7
8 Data presentation. 9
9 Exchange file format. 10
Annex A (informative) Determination of maximum measurable impedance with the open-lead test . 11
Annex B (normative) Data exchange file format . 13
Bibliography . 17

ISO 16773-2:2007(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 16773-2 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
1)
⎯ Part 3: Processing and analysis of data from dummy cells
1)
⎯ Part 4: Examples of spectra of polymer-coated specimens

1) In preparation.
iv © ISO 2007 – All rights reserved

INTERNATIONAL STANDARD ISO 16773-2:2007(E)

Paints and varnishes — Electrochemical impedance
spectroscopy (EIS) on high-impedance coated specimens —
Part 2:
Collection of data
1 Scope
This part of ISO 16773 provides guidance on optimizing the collection of EIS data from high-impedance
systems. High impedance in the context of intact coatings refers to systems with an impedance greater than
9 2
10 Ω⋅cm . This does not preclude measurements on systems with lower impedance.
This part of ISO 16773 deals with
⎯ instrumental set-up: requirements and pit-falls;
⎯ data validation: checking the measurement range and the accuracy of the data;
⎯ performing an EIS measurement: specimen considerations and instrumental parameters;
⎯ the experimental results: different methods of presenting EIS data.
Following the recommendations should ensure the acquisition of EIS data that can be used to study the
performance of the specimen. It does not give guidelines for the interpretation of the data.
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 16773-1, Paints and varnishes — Electrochemical impedance spectroscopy (EIS) on high-impedance
coated specimens — Part 1: Terms and definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16773-1 apply.
4 Principle
A so-called “confidence” test is described in order to check the suitability of the entire set-up and
recommendations are given as to how to perform EIS experiments. For convenience, only potentiostatically
controlled EIS measurements are described, although it is also possible to make EIS measurements under
galvanostatic control.
A potentiostat is connected either to a dummy cell or to an electrochemical cell (with working, counter- and
reference electrodes). A single-sinusoidal- or multi-sinusoidal-waveform potential, either in conjunction with a
d.c. offset or not, is applied by the potentiostat to the dummy cell or to the electrochemical cell, and the
resulting a.c. current is measured. Both potential and a.c. current data are collected and analysed for
amplitude and phase shift. This can be done in a variety of ways, depending on the type of equipment used.
ISO 16773-2:2007(E)
All data are presented and compared graphically, or computed for equivalent circuits. In the case of the
dummy cell, the values of these equivalent components are compared to the actual cell components
connected to the potentiostat and evaluated for coherence.
5 Electrochemical cell
5.1 General
NOTE 1 Various types of measurement cell exist which are suitable for use with this part of ISO 16773. Most
commonly used are two-electrode and three-electrode arrangements for measurements in an aqueous electrolyte.
The cell should be constructed of materials that will not corrode, otherwise deteriorate or contaminate the
solution (e.g. PMMA, PTFE or glass). A material compatibility test should be carried out.
The cell should be leak-proof to ensure that the geometrical surface of the specimen does not change with
time.
The cell should preferably be designed to allow the following items to be inserted into the electrolyte chamber:
the working electrode, the reference electrode, the counter-electrode, a thermometer (for temperature control)
and gas inlet/outlet tubes to modify the oxygen content of the electrolyte. When using an inert gas, a gas
scrubber should be used.
An example of an electrochemical cell is shown in Figure 1.

Key
1 reference electrode
2 counter-electrode
3 electrolyte
4 O-ring
5 coating
6 working electrode
Figure 1 — Example of an electrochemical cell
NOTE 2 This drawing does not imply that other designs are unsuitable.
The components shown in Figure 1 are described in 5.2 to 5.4.
2 © ISO 2007 – All rights reserved

ISO 16773-2:2007(E)
5.2 Electrodes
To perform EIS in aqueous solution, the more conventional set-up is composed of a three-electrode
arrangement: a working electrode, a reference electrode and a counter-electrode.
Working electrode: A conductive substrate covered by the coating to be investigated. A large surface area is
preferred to better take into account any defects and to decrease the impedance of the system to give a better
signal-to-noise ratio.
Counter-electrode: Inert material such as platinum with a large surface area oriented parallel to the working
electrode in order to ensure a homogeneous current distribution.
Reference electrode: A low-impedance and low-noise reference electrode is recommended [in the context of
this part of ISO 16773, a salt bridge (e.g. Luggin capillary) is not required]. The potential of the reference
electrode should be checked periodically to control the accuracy of the electrode and its stability with time. At
very high frequencies, the presence of the reference electrode can induce some spurious effects.
NOTE 1 To improve the quality of the high-frequency signal, a platinum wire with a capacitor may be placed in parallel
with the reference electrode. The capacitor ensures that the d.c. potential is coming from the reference electrode and a.c.
potential from the platinum wire.
NOTE 2 For specific applications it can be acceptable to use a pseudo-reference electrode consisting of an inert
material such as a high-nickel alloy or a chloridized silver wire. Pseudo-reference electrodes are useful for measurements
in the field, where a reference electrode can be easily broken.
5.3 Exposed area
The exposed area should be accurately known, constant with time, and should be adequate for the
investigation. Large areas make the measurement more sensitive for single defects (pores) and give better
signal-to-noise ratio.
5.4 Electrolyte
The resistance of the solution should be low in comparison to the impedance of the investigated system.
Different types of electrolyte can be used. Non-aggressive electrolytes can be employed to characterize the
properties of the system without introducing corrosion. An aggressive solution may be selected to characterize
the corrosion resistance of the system. The electrolyte should be chosen with the end use of the coating in
mind.
6 Procedure
6.1 Grounding
An EIS instrument consists of a potentiostat, a computer and a module or instrument specifically required for
the impedance measurement.
Electrical grounding considerations between the instruments, the specimen and the environment are important,
both for the safety of the operator and the acquisition of as accurate and noise-free EIS data as possible.
a) The safety of the operator is important. The chassis of the EIS instrument should be connected to ground
to avoid a potentially lethal electrical shock if the instrument malfunctions. The chassis is normally
grounded through the connection to the a.c. mains. Under no circumstances should this connection to
ground be bypassed.
b) In most cases, the coated specimen is tested in the laboratory in an electrochemical cell such as that
described in 5.1 in which the specimen is electrically isolated from ground, or “floating”. This is the
simplest case with no special consideration needed for connection of the instrument to the specimen.
ISO 16773-2:2007(E)
c) If, however, the coated specimen is grounded, then the grounding considerations become more complex.
This could happen if EIS is used to test coated structures in a field such as vessels or pipelines. If the
coated specimen is grounded, then the EIS instrument should be electrically isolated from ground to
obtain accurate EIS data. This is not a trivial consideration and is generally taken into account during the
design of the EIS system. Floating the EIS system by bypassing the protective ground connection to the
mains is a safety hazard and is not acceptable.
d) When connecting up the various instruments and computers, it is possible to inadvertently ground a
floating instrument through the connection to a grounded instrument. This can give rise to noise through
“ground loops” or even result in improper operation.
6.2 Shielding
Shielding is very important for noise considerations in EIS measurements of high-impedance specimens.
Proper shielding will ensure that the cell electrodes and cables will not pick up electromagnetic radiation from
the surroundings. The electrochemical cell should be placed inside a Faraday cage and the Faraday cage
connected to an appropriate ground connection of the potentiostat. If the potentiostat has an externally
mounted electrometer, the electrometer should also be put inside the Faraday cage. The manufacturer's
manual should be consulted to ensure proper wiring.
6.3 Cell cable ground contacts
The connections between the cell cables and the cell should be clean and the length of the cables should be
as short as possible to minimize stray capacitance.
6.4 Local conditions
The following conditions in the vicinity of the EIS experiment can affect the quality of the measurement.
a) The incoming a.c. power to the EIS instrument can be noisy or exhibit large voltage transients, both of
which can result in noise in the electrochemical data. If severe, the user may install an a.c. line
conditioner. The raw potential and current data are usually averaged by the EIS instrument and are not as
susceptible to line noise as d.c. experiments.
b) Electromagnetic noise from electrical devices (e.g. computer monitors) in the local vicinity of the EIS
experiment can also contribute to noise in the experiment. Again, data processing will discriminate
against this noise. Instruments or appliances that operate intermittently (e.g. freezers, ovens, ultrasonic
cleaners, magnetic stirrers, water baths) are particularly troublesome because they can introduce noise in
the electrical circuit when they are activated. These devices should be operated on a different circuit, if
possible. Because of the low current levels which are typically observed in EIS experiments on coated
specimens, the specimen should always be contained in a Faraday cage that is connected to the
appropriate instrument ground.
c) The relative humidity in the environment can also be of concern. If the relative humidity is high, then
micro-condensation can occur in the electronics of the EIS instrument, providing a low-impedance
leakage path. At the low current levels typically encountered in EIS experiments on coated specimens,
this can result in errors in the current measurement.
6.5 Measurement equipment characteristics
An electrochemical cell has impedance values that can range from 1 mΩ to more than 1 TΩ (10 Ω). The
measured impedance of coated specimens can range up to 10 Ω.
A specimen with high impedance will exhibit very low current flow during the EIS experiment. Therefore, the
instrument used to measure the EIS of coated specimens needs to be capable of measuring these low
currents. The test described in 6.6 is useful to make sure an EIS instrument is capable of measuring coated
specimens.
All equipment should be able to measure the dummy cell described in 6.6.1.
4 © ISO 2007 – All rights reserved

ISO 16773-2:2007(E)
Sometimes, it might be desirable to perform an open-lead test in order to find the limits of the entire set-up
under the given conditions. A method of estimating the maximum measurable impedance with the open-lead
test is given in Annex A.
NOTE EIS measurements on high-impedance coatings are not limited to the above-mentioned cell designs.
6.6 Confidence test
6.6.1 General
In order to obtain confidence in the entire experimental set-up, it is recommended that a confidence test be
carried out prior to measurements of real specimens. Confidence can be obtained by carrying out reference
tests using hard-wired dummy circuits with known values for capacitance and resistance. These values should
be in the order of magnitude which can be expected for the actual coated specimen under investigation. As
high-impedance coatings easily reach values of several gigaohms, combined with low capacitance of about
100 pF, it is recommended that the circuit in Figure 2 be used as a reference.

R1 = 50 GΩ
C1 = 150 pF
Rs = 50 Ω
Figure 2 — Dummy cell for confidence test
6.6.2 Use of interlaboratory test cells for confidence test
Because significant knowledge has been gathered during the performance of a related interlaboratory test,
similar circuits with similar values, as used in the interlaboratory test, could be used for the confidence test.
NOTE Details are given in Part 3 of this International Standard.
6.6.3 Error estimate and accuracy
Data for error estimate, accuracy, reproducibility and repeatability are not currently available. They will be
provided after the completion of an interlaboratory test.
6.7 Specimens
6.7.1 Preconditioning of specimens
Proper preparation and preconditioning of coated specimens is critical for successful and reliable EIS data.
6.7.2 Environmental control
The coating should be applied and cured in accordance with the manufacturer’s recommendation unless
otherwise agreed upon between the participating parties.
The film thickness should be as uniform as possible. The exact film thickness should be measured and
reported (e.g. in accordance with ISO 2808).
Temperature and humidity control during the application, curing, conditioning and impedance measurement of
organic coatings is crucial for a proper determination of the coating resistance.
ISO 16773-2:2007(E)
The temperature of the specimens during the impedance measurements should be held constant to within
± 2 °C, preferably within ± 1 °C. Relative values for comparison between specimens outside these guidelines
are acceptable if all the specimens are run under the same conditions.
When the coating capacitance is the main parameter of interest, control of relative humidity during specimen
conditioning is very important. To ensure accurate conditioning, the humidity should be (50 ± 5) % in
accordance with ISO 3270, if not as otherwise agreed.
For reliable measurements, temperature control should be equal to or better than ± 1 °C. For conditioning
prior t
...