EN ISO 2808:1999
(Main)Paints and varnishes - Determination of film thickness (ISO 2808:1997)
Paints and varnishes - Determination of film thickness (ISO 2808:1997)
Migrated from Progress Sheet (TC Comment) (2000-07-10): BT C 9/1996 approved VA/ISO, but too late (PQ or UAP on revised ISO 2808 when ++ available).
Beschichtungsstoffe - Bestimmung der Schichtdicke (ISO 2808:1997)
Diese Internationale Norm behandelt und legt eine Anzahl von Verfahren für die Messung der Dicke von organischen Beschichtungen, welche auf ein Substrat aufgetragen wurden, fest. Diese Internationale Norm gilt nicht für metallische Überzüge. Einige der beschriebenen Verfahren können auch für die Messung der Dicke von abgelösten Beschichtungen angepaßt werden. Die Prinzipien der Verfahren, ihre besonderen Anwendungsbereiche und die erwartete Präzision werden in Tabelle 1 angegeben. Diese Internationale Norm definiert auch Begriffe, welche die Bestimmung der Schichtdicke betreffen.
Peintures et vernis - Détermination de l'épaisseur du feuil (ISO 2808:1997)
L'IEC 61837-4:2015 spécifie les dessins d'encombrement et les connexions des sorties pour les dispositifs piézoélectriques à montage en surface avec les encombrements d'enveloppes hybrides, et est fondée sur l'IEC 61240:2012, qui a normalisé les règles de tracé des dessins d'encombrement des dispositifs à montage en surface. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- Le dessin d'encombrement est défini comme un ensemble de dessins composé de quatre vues, à savoir la vue de dessus, la vue de face, la vue de droite et la vue de dessous, à la place de l'ensemble des trois vues prévu dans la version précédente.
- Les configurations des enveloppes ont été révisées comme indiqué au Tableau 1.
Cette publication doit être lue conjointement avec la CEI 61240:2012.
Barve in laki - Ugotavljanje debeline plasti (ISO 2808:1997)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 2808:1999
01-december-1999
Barve in laki - Ugotavljanje debeline plasti (ISO 2808:1997)
Paints and varnishes - Determination of film thickness (ISO 2808:1997)
Beschichtungsstoffe - Bestimmung der Schichtdicke (ISO 2808:1997)
Peintures et vernis - Détermination de l'épaisseur du feuil (ISO 2808:1997)
Ta slovenski standard je istoveten z: EN ISO 2808:1999
ICS:
87.040 Barve in laki Paints and varnishes
SIST EN ISO 2808:1999 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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Is0
INTERNATIONAL
2808
STANDARD
Third edition
1997-09-l 5
Paints and varnishes - Determination
of film thickness
Dbtermination de I’hpaisseur du feuil
Peintures et vernis -
Reference number
IS0 2808: 1997(E)
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IS0 2808:1997(E) .
Contents
1
Scope
8
Normative references
9
Required supplementary information
9
Definitions
1
10
General requirements
11
Method No 1 - Determination of wet-film thickness
Method No 2 - Determination of dry-film thickness by calculation
17
from film mass per unit area
Method No 3 - Measurement of dry-film thickness by mechanically
18
contacting methods
21
Measurement of dry-film thickness by the profilometer method
Method No 4 -
22
microscope methods
10 Method No 5 - Measurement of dry-film thickness using
- Magnetic method 29
11 Method No 6
30
12 Method No 7 - Eddy current method
8 - Non-contact methods 31
13 Method No
33
14 Method No 9 - Gravimetric method (dissolving method)
15 Method No 10 - Determination of dry-film thickness on blast-cleaned steel
33
substrates
35
16 Test report
Annexes
37
A Method No 2 - Procedure
0 IS0 1997
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
microfiim, without permission in writing from the publisher.
lnternational Organization for Standardization
Case postale 56 l CH-1211 Geneve 20 l Switzerland
Internet central @ iso.ch
x.400 c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
ii
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IS0 2808:1997(E)
@ IS0
Foreword
IS0 (the International Organization for Standardization) is a worldwide federation of national
standards bodies (IS0 member bodies). The work of preparing International Standards is
normally carried out through IS0 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. IS0 collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
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.
International Standard IS0 2808 was prepared by Technical Committee ISO/TC 35, Paints
and varnishes, Subcommittee SC 9, General test methods for paints and varnishes.
This third edition cancels and replaces the second edition (IS0 2808: 1991) of which it
constitutes a technical revision.
The main technical changes are:
a) Addition of the following methods of film thickness determination:
1) Gravimetric (dissolving) method (Method 9)
2) Determination of dry-film thickness on blast-cleaned steel substrates (Method 10).
b) Table 1 includes typical instrument bias and precision for each method.
Annex A forms an integral part of this International Standard.
. . .
III
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INTERNATIONAL STANDARD @ IS0 IS0 2808:1997(E)
Paints and varnishes - Determination of film thickness
1 Scope
This International Standard reviews and specifies a number of methods that are applicable to
the measurement of the thickness of organic coatings applied to a substrate. It does not apply
to metallic coatings. Some of the techniques described can be adapted for the measurement of
the thickness of detached coatings. The principles of the methods, their particular field of
application and the expected precision are given in table 1.
This International Standard also defines terms concerning the determination of film thickness.
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.G
Table 1 - Methods of film thickness measurement
0
N
$
Note 1: Many of the methods referred to below may be adapted for use with detached films.
00
=;
co
Typical instrument bias 1) and Remarks (0
Techniques and applications
Number and description
2
precision
m
---II
Measurements give an
A Comb gauge
Method No. 1
approximate indication of the
thickness of the wet film.
Bias: * 2,5 % + 1 pm May be used in laboratories and
B Wheel gauge
Assessment of wet-film thickness
on site.
Method 1C may also be used for
Reproducibility: k 15 pm
C By weighing
determining the dry-film
For measurement of wet-film
thickness, but in the laboratory
thickness of freshly painted
only.
surfaces.
Determinations are not precise Provides a check that the mean
For use on films too soft to be
Method No. 2
thickness lies between specified
measured by methods which use
limits. The fi m remains
a presser foot or probe.
Determination of dry-film
undamaged.
thickness by calculation from the
ratio of dry-film mass to dry-film
area
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Method No. 3
A Micrometer method. For use Bias: k 2 pm The film has to be hard enough to
Measurement of dry-film on test panels or painted surfaces Reproducibility: k 30 % for low resist indentation on closing the
thickness by mechanically that are substantially plane. and 20 o/s for higher film micrometer jaws. The film is
contacting instruments damaged in the test. The film
thicknesses
thickness shall be greater than
25 pm unless the film is
detached.
B Dial gauge method Reproducibility: * 10 %, with a The film has to be hard enough to
Test panels or painted surfaces lower limit of 2 pm resist indentation on lowering the
that are substantially plane or gauge or electric-device presser
have a curvature in one direction foot.
Method No. 4
Recommended as a referee Reproducibility: k 10 %, with a The film has to be hard enough to
Measurement of dry-film method for painted surfaces that
lower limit of 2 pm resist indentation by the
thickness by the profilometric are substantially plane. profile-tracing stylus.
method The film is damaged in the test.
m
63
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Method No. 5
A portion of the painted article is
Bias: 2 pm
A Microscopic examination of
cut out and mounted in resin.
Measurement of dry-film cross-section.
Reproducibility: * 10 % The film is damaged in the test.
Recommended as a referee
thickness by microscope methods
method for films on substrates of
varying profile, for example
grit-blasted surfaces.
A special cutting tool or paint
B Wedge cut method. Reproducibility: zfi 10 %, with a
borer is required to cut through
Not applicable to brittle or friable lower limit of 2 pm
the film.
films.
The film is damaged in the test.
Both A and B can be used for
thicknesses of individual coats in
a paint system
A special microscope is used to
C Surface profile measuring Reproducibility: * 10 %
method. Applies to transparent examine the profile of the film
(split-beam microscope).
films and to films which can be
cleanly removed from the Only transparent films remain
undamaged.
substrate.
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ISO2808:1997(E)
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Instruments operate on the
Used when contact by the
Method No. 8
beta-particle back-scatter
measuring instrument with the
principle (method No. 8A) or the
Non-contact methods coating needs to be avoided.
X-ray fluorescence principle
Applicable to painted surfaces
Reproducibility: k 10 % (method No. 8B).
which are substantially flat.
Paint films have to be
homogeneous for measurements
to be accurate.
The coating mass is determined
Method No. 9 Applicable to films on substrates
of varying profiles, for example by dissolving the coating without
Gravimetric (dissolving) method dissolving the substrate. The
grit-blasted steel panels, and to
mass of coating divided by the
films on polymeric substrates if
the substrate is not affected by density and the area of the
the paint solvent. coating gives the average coating
thickness.
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Method No. 10 For dry coatings on magnetic Instruments operate on the
metallic substrates having a magnetic-induction principle.
rough (blast-cleaned) surface.
Determination of dry-film May be used on site.
thickness on blast-cleaned steel In some cases, method No. 5A or
substrates
method No. 9 may also be used.
1) The bias data are based on
information supplied by the
instrument manufacturers
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IS0 2808: 1997(E)
2 Normative References
The following standards contain provisions which, through reference in this text, constitute
provisions of this International Standard. At the time of publication, the editions indicated
were valid. Ail standards are subject to revision, and parties to agreements based on this
International Standard are encouraged to investigate the possibility of applying the most
recent editions of the standards listed below. Members of IEC and IS0 maintain registers of
currently valid International Standards.
IS0 1463 : 1982, Metallic and oxide coatings - Measurement of coating thickness -
Microscopical method
IS0 15 14: 1993, Paints and varnishes - Standard panels for testing
IS0 2 178: 1982, Non-magnetic coatings on magnetic substrates - Measurement of coating
thickness - Magnetic method
IS0 2360: 1982, Non -conductive coatings on non-magnetic basis metals - Measurement of
coating thickness - Eddy current method
IS0 28 11: 1997, Paints and varnishes - Determination of density -
Part 1: Pyknometer method
Part 2: Immersed body (plummet) method
Part 3: Oscillation method
Part 4: Pressure cup method
IS0 3233: 1984,‘) Paints and varnishes - Determination of volume of dry coating (non-volatile
matters) obtained from a given volume of liquid coating.
IS0 3497: 1990, Metallic coatings - Measurement of coating thickness - X-ray spectrometric
methods
IS0 3543 : 198 1, Metallic and non-metallic coatings - Measurement of thickness - Beta
backscatter method
IS0 45 18: 1980, Metallic.coatings - Measurement of coating thickness - Profilometric
method
IS0 7254: 1984, Paints and varnishes - Assessment of natural spreading rate - Brush
application
IS0 8503-l : 1988, Preparation of steel substrates before application of paints and related
products - Surface roughness characteristics of blast-cleaned steel substrates - Part 1:
Specifications and definitions for IS0 surface profile comparators for the assessment of
abrasive blast-cleaned surfaces.
1) Under revision.
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IS0 2808:1997(E)
3 Required supplementary information
The methods of measurement specified require to be completed, for any particular
application, by the following supplementary information.
This information should be derived from the International Standard or national standard or
other document for the product under test or, if appropriate, may be the subject of agreement
between the interested parties.
a) The method of application of the coating to the substrate and whether it is a single
coating or a multi-coat system.
b) The duration and conditions of drying (or stoving) and ageing (if applicable) of the
coating before measurement.
c) The method of film thickness measurement to be used (see table 1).
d) The significant area ( see 4.2) of the coated article and, if necessary, the number of
measurements.
4 Definitions
For the purpose of this International Standard, the following definitions apply:
4.1 film thickness: The thickness of a coating applied to a substrate is the distance between
the surface of the film and the surface of the substrate.
NOTE 1 - The value of a film thickness depends, to some extent, on the method of
measurement used. To give a correct value would only be possible if the coating and
substrate had flat and even surfaces. In practice, neither the surface of the coating nor the
surface of the substrates is even. In many cases, the surface irregularities exceed 10% of
the film thickness. The results of the measurements by different methods are influenced by
these irregularities. The influence is different for each method. Therefore, the results of
different methods applied to the same specimen may differ markedly. This is the reason
why the results of film thickness measurements always have to be reported together with
information on the method of measurement and which type of instrument was used, plus
the bias of the instrument, if known.
4.2 significant surface area: That part of an article covered or to be covered by the coating
and for which the coating is essential for serviceability and/or appearance.
4.3 reference area: That part of the significant surface area within which a specified number
of single measurements are required to be made.
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IS0 2808: 1997(E)
4.4 measurement area: The area over which a single measurement is made.
In this International Standard the measurement area (test area) is specified as follows:
a) for analytical (dissolution) methods, the area over which the coating is removed; i
b) for microscopical methods, the point at which a single measurement is made;
c) for non-destructive methods, the probe area or the area influencing the reading.
4.5 local film thickness: The mean of the specified number of thickness measurements made
within a given reference area,
4.6 minimum local film thickness: The lowest value of the local thicknesses found on the
significant surface area of a particular article.
4.7 maximum local thickness: The highest value of the local thicknesses found on the’
significant surface area of a particular article.
4.8 mean film thickness: The mean value of a specified number of local thickness
measurements that are evenly distributed over a significant surface area, or the result of a
3
gravimetric film thickness determination.
4.9 wet-film thickness: The thickness of a freshly applied coating material, measured
immediately after application.
5 General. requirements
5.1 General
In this standard, information is given concerning the number and location of measurement
areas to be adopted when determining paint film thickness on typical test panels (see
IS0 15 14). On other test panels and on painted articles the number and location of test areas
shall be such as to provide as the measurement result a representative film thickness and shall
be the subject of agreement between the interested parties.
’ Follow the manufacturer’s instructions for operation of the instruments.
Always check the instruments for repeatability. Check calibration and the condition of the
probe tip at regular intervals.
Make sure that the pressure of the probe tip does not alter the film thickness significantly.
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@ IS0 lSO2808:1997(E)
5.2 Rough surfaces
The surface roughness of the substrate influences the determination of film thickness. For the
optical methods it is proposed to agree upon reference lines or areas.
If a non-destructive method is used, the calibration of the instrument has to be made and
checked on the same kind of uncoated substrate as is used for the test piece.
For blast-cleaned steel substrates, special conditions apply (see method No. 10).
5.3 Edge effect
Some instruments are affected by the presence of an edge of the article, and of these some can
be calibrated to allow for this effect. Measurement shall be made at more than 25 mm from
the edge of an article or panel or at the distance from the edge for which the instrument has
been calibrated.
5.4 Surface curvature
Some instruments are particularly sensitive to surface curvature and must always be
calibrated using samples of the same curvature as the test piece.
6 Method No.1 - Determination of wet-film thickness
6.1 General
This method describes three ways of measuring the thickness of wet paint films.
It can be used to measure the spreading rate of a paint.
The equation linking the spreading rate, A,, in m2/L, and the wet-film thickness, t,Jn pm, is
A 1000
s=-
t W
NOTE2 - The spreading rate is usually determined using IS0 7254.
In addition, by using a suitable correlation procedure, it is possible to estimate the
approximate thickness of a dry film, by measuring its wet film thickness immediately after
application. This is useful when dry film thickness methods are destructive or not very
accurate, e.g. on wood or masonry substrates. The dry film thickness is calculated using the
following equation:
11
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@ IS0
IS0 2808: 1997(E)
V
tD =twXS
100
where
tD = dry film thickness in micrometres
= wet film thickness in micrometres
tW
Vs = percentage non-volatile content by volume
The method described is suitable for use on rigid substrates with a suitable surface profile.
The method may be used both in the laboratory and on site to check paint application.
6.2 Method 1A - Comb gauge
6.2.1 Apparatus
The gauge consists of a comb made of stainless steel or of a suitable plastic unaffected by the
solvents in the paint, the outer teeth of which form a baseline. The inner teeth are
progressively shorter so as to present a range of gaps between the teeth and the baseline, and
the size of each gap can be read from a scale on the gauge. A typical comb gauge is illustrated
in figure 1.
6.2.2 Procedure
Immediately after the application of the paint, place the comb gauge firmly onto the substrate
in such a way that the teeth are normal to the plane of the surface and the gauge does not slip.’
Remove the gauge, and examine the teeth to determine which is the shortest one to touch the
wet paint film. Record the film thickness as a range lying between the last ‘touching’ tooth
and first ‘non-touching’ tooth as shown on the tooth calibrations marked on the gauge.
Take at least two further measurements in different places in the same manner to obtain
representative results over the painted area.
12
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@ IS0 IS0 2808:1997(E)
Dimensions in miilimetres, except for the gauge
graduations
ln
2s
1
t I
600
7
A
b
2s
-c
Not to scale: the differences between the lengths of the teeth are exaggerated for clarity.
NOTE - The comb illustrated is for 25 pm to 600 pm; combs are available in a range
of scales.
Figure 1
Comb gauge
13
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@ IS0
IS0 2808: 1997(E)
6.3 Method 1B - Wheel gauge
6.3.1 Apparatus
The gauge consists of a wheel of which the perimeter has three equally spaced rims, the
central one of which is smaller than and eccentric to the outer ones. When the gauge is rolled
over a wet film, the eccentric central rim shows a position at which it just touches the wet
paint surface, and a calibrated scale engraved on the outer wheel enables the wet paint
thickness at this point to be noted. A range of gauges is available. A typical gauge showing a
calibration series is shown in figure 2.
Several measurements are taken in the same manner to obtain representative results over the
painted area.
The touch of wet film and eccentric rim is influenced by the surface tension of the paint.
Hence it is necessary to observe first and last touch and to calculate the mean.
14
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IS0 2808: 1997(E)
Dimensions in micrometres
cv
+I
z
I
I n r
1
- -
.
----pm--
.
?
- -
Centre level with
outer rims
L Year
Serial No
Figure 2
Typical wheel gauge
15
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@ IS0
IS0 2808: 1997(E)
6.3.2 Procedure
Immediately after the application of the paint, place the rims of the wheel gauge into the paint
film so that the two outer rims are in contact with the substrate at the point of maximum gap
(i.e. the largest reading on the scale). Rotate the wheel through nearly 360° along the surface
and remove.
Examine the centre rim to determine the position at which contact was made with the wet
film. For uneven films, note the first and last complete and continuous contact made with the
film surface. The scale shows the wet-film thickness at these points. Read the film thickness
at the next lower and next higher scale divisions and calculate the mean. Record the result.
Repeat the procedure at least twice in different places in a similar manner to obtain
representative results over the painted area.
6.4 Method 1C - By weighing
This method is applicable to test pieces of conveniently measurable area which fit on a
suitably sensitive balance.
This method is also suitable for dry-film thickness measurement.
This method is not suitable for paints containing fast-evaporating solvents.
6.4.1 Procedure
6.4.1.1 Measure the linear dimensions of the test pieces to an accuracy of 1 % and calculate
the surface area of the face to be painted.
6.4.1.2 Weigh the test piece to the nearest 1 mg.
6.4.1.3 Coat the test piece and reweigh to the nearest 1 mg while wet. (as soon as possible
after coating) and after drying.
16
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@ IS0
IS0 2808: 1997(E)
6.4.1.4 Calculate the wet-film thickness in pm from the following equation:
Mw- Mp
tw =
Al? .
W
Where
M = mass, in grams of the wet coated test piece
W
3
M = mass, in grams, of the test piece alone
P
A = area in square metres of the test piece
l w = density in grams per millilitre of the wet paint.
The density of the wet paint can be determined using one of the parts of IS0 2811.
6.4.1.5 Calculate the dry film thickness from the following equation:
Ah- Mp
td =
Al? . d
Where
!vfd = mass, in grams, of the dried coated test piece
!d = density, in grams per millilitre, of the dried film.
The density of the dried film can be determined using IS0 3233.
7 Method No 2 - Determination of dry-film thickness by calculation from film mass per
unit area
7.1 General
This method describes a way of checking that the thickness of a dried film of paint on a test
panel lies within the limits specified. It is not intended to give a precise measurement of the
actual thickness of the film.
The measurement is obtained by reference to a graph showing the relationship between film
thickness and film mass for the product under test.
17
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@ IS0
ISO2808:1997(E)
It is intended for use with air-drying paints that produce films requiring several days before
they are sufficiently hard to permit thickness measurements by instrumental methods. It gives
an overall mean value for the thickness of the paint film based on its dry mass and does not
cause any mechanical damage to the paint film.
7.2 Procedure
Details of the method are given in annex A.
NOTE 3 - Method 1C (see 6.4) can also be used to measure dry-film thicknesses.
8 Method No 3 - Measurement of dry-film thickness by mechanically contacting
methods
Measurements are made on coatings after the film has dried to a condition that the jaws of the
micrometer or the presser foot of the dial gauge do not produce any visible indentation in the
film.
The method is only suitable for painted panels or articles that are substantially plane or of
circular cross-section (e.g. wire) and for coatings that can be removed by solvent or paint
remover.
8.1 Method 3A - Micrometer method
8.1.1 General
This method describes a means for measuring, to within 5 pm, the thickness of a dried paint
film on a painted article or test panel.
8.1.2 Apparatus
Suitable micrometer, capable of measurement to 5 pm or less, fitted with a ratchet.
8.1.3 Procedure
8.1.3.1 Select positions, where readings are to be taken, that are free from surface
irregularities and are not less than 20 mm from any paint film edge and not less than
approximately 50 mm apart.
For large areas, select the number and distribution of the testareas to give a representative
indication of the film thickness.
18.
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lSOi2808:1997(E)
Mark an area around each test position by lightly drawing a circle approximately 10 mm in
diameter and designate each position with a different reference number alongside.
8.1.3.2 Support the painted specimen rigidly in a manner such that all the test positions are
accessible to the micrometer (8.1.2).
8.1.3.3 Position the micrometer with the fixed jaw in plane contact with the underside of the
test specimen and immediately opposite the first test area. Gently screw home the movable
jaw until a resistance is felt and no further movement of the jaw occurs on turning the ratchet.
Note the reading on the micrometer, using an underlying mirror if necessary to read the
vernier scale. Record the reading and the position reference number on a test record sheet.
Release the micrometer and repeat the whole procedure at each of the other test positions.
Carefully remove the paint film from within the circle at each test area with a
8.1.3.4
suitable solvent or paint remover, taking care not to obliterate the distinctive number. This
may be done by covering the test area with a small circle of thick filter paper and applying to
it a few drops of a suitable solvent.
Measure the thickness of the substrate by repeating the procedures 8.1.3.2 and 8.1.3.3 at each
test area.
NOTE 4 - The thickness of the substrate can sometimes be measured before painting in
order to avoid having to remove the paint.
8.1.4 Calculation
8.1.4.1 Calculate the film thickness at each test position by subtracting the reading obtained
after removal of the film from that obtained before removal.
8.1.4.2 Calculate the mean value for the thickness of the film on the test panel to the nearest
multiple of 5 pm or less (depending on the accuracy of the micrometer).
8.2 Method 3B - Dial gauge method
8.2.1 General
This method describes a means for measuring, to an accuracy of within 2 pm, the thickness of
a dried paint film on a painted article or test panel.
19
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IS0 2808:1997(E)
8.2.2 Apparatus
Dial gauge or any suitable indicator for linear measurement, having a mechanically
contacting foot and mechanical, optical, or electronic read-out, capable of measurement to an
accuracy of 2 pm, mounted on a rigid support.
8.2.3 Procedure
8.2.3.1 Select positions, where readings are to be taken, that are free from surface
irregularities and are not less than 20 mm from any paint film edge and not less than
approximately 50 mm apart.
For large areas, select the number and distribution of measuring areas to give a representative
indication of the film thickness.
Mark an area around each test position by lightly drawing a circle approximately 10 mm in
I
diameter and designate each position with a different reference number alongside.
8.2.3.2 Support the painted specimen rigidly in a manner such that neither the Eowering of
the presser foot nor the removing of the paint film allow any movement of the specimen.
Place the indicator vertical to the test panel so that the presser foot is immediately above the
centre of the first measuring area. Carefully lower the presser foot until it is in good contact
with the paint film. Record the reading and the measuring area reference number on a test
record sheet. Lower the presser foot several times and record the readings.
Raise the presser foot and carefully remove the paint film within the circle of the measuring
area with a suitable solvent or paint remover. This may be done by covering the test area with
a small circle of thick filter paper and applying to it a few drops of a suitable solvent.
Carefully lower the presser foot until it is in good contact with the cleaned surface of the
substrate and record the reading. Measure several times.
8.2.3.3 Repeat the procedure at each measuring area.
8.2.4 Calculation
8.2.4.1 Calculate the film thickness at each test position by subtracting the reading obtained
after removal of the film from that obtained before removal.
8.2.4.2 Calculate the mean value of the thickness of the film on the test panel to the nearest
multiple of 2 pm
20
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IS0 2808: 1997(E)
9 Method No. 4 - Measurement of dry-film thickness by the profilometer method
9.1 General
This method describes a procedure for measuring the thickness of a hard dried paint film (i.e.
one hard enough not to be penetrated or deformed by the profilometer stylus) on a painted
article or test panel to within 2pm.
NOTE 5 - For reliable results, the minimum coating thickness should be not less than 10
times the roughness amplitude of the substrate.
The measurement is
...
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