ASTM D1212-91(2007)e1

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D1212 − 91 (Reapproved2007)
Standard Test Methods for
Measurement of Wet Film Thickness of Organic Coatings
This standard is issued under the fixed designation D1212; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
´ NOTE—Research report was added editorially to Test Method B in April 2012.
1. Scope 3.2 In Test Method A, a gage with one eccentric and two
concentricwheelsisrolledoverthesurfaceandthepointwhere
1.1 These test methods cover the determination of wet film
the eccentric wheel first touches the wet film is determined.
thickness of organic coatings such as paint, varnish, and
3.3 InTest Method B, a gage with a convex lower surface is
lacquer. Two methods are described as follows:
pushed into the wet film until the center touches the substrate.
1.1.1 In Test Method A, the Wet Film Thickness Gage
The diameter of the spot of wet coating left on the convex
(English or Metric graduation (see 5.1)) is used to measure wet
surface is measured and the film thickness calculated from the
film thicknesses up to 60 mils on the English scale series, and
diameter of the spot and the radius of curvature.
up to 700 µm on the metric scale series (Sections 5-8).
1.1.2 In Test Method B, the Pfund Gage is used to measure
4. Significance and Use
wet film thicknesses up to 14.2 mils (360 µm) (Sections 9-13).
4.1 Wet film thickness measurements aid in the prediction
1.2 The values stated in SI units are to be regarded as the
of dry film thickness. In instances where dry film thickness
standard. The values given in parentheses are for information
cannot be measured nondestructively, wet film thickness is
only.
frequently specified. Also, the ability to determine wet film
1.3 This standard does not purport to address all of the
thickness during application can provide the opportunity to
safety concerns, if any, associated with its use. It is the
correct the application procedures.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
TEST METHOD A
bility of regulatory limitations prior to use.
5. Apparatus
2. Referenced Documents
5.1 WetFilmThicknessGage—Twoversionsofthegageare
2.1 ASTM Standards:
now in use: The original design as shown in Fig. 1 and a later
D823 Practices for Producing Films of Uniform Thickness
designasshowninFig.2.Bothdesignsconsistsofaneccentric
of Paint, Varnish, and Related Products on Test Panels
center wheel supported by two concentric wheels so as to
providetwoscalesthatarebilaterallysymmetrical.Asthegage
3. Summary of Test Methods
is rolled on the film, there is a change in clearance between the
3.1 The material is applied in the laboratory to plane, rigid wet film and the eccentric wheel. The point at which the film
test panels or in the field to the surface being coated. The wet first touches the center wheel measures the thickness of the
film thickness is determined as quickly as possible to reduce film.
shrinkage due to solvent loss.
5.2 The later design shown in Fig. 2, moves the eccentric
wheel from between the concentric wheels, as shown in Fig. 1,
to the outside of the gage and closer to one of the concentric
These test methods are under the jurisdiction of ASTM Committee D01 on wheels. Gage reading errors of parallax across the gage are
Paint and Related Coatings, Materials, and Applications and are the direct
eliminatedasthetwoscalesareplaceddirectlyontheeccentric
responsibility of Subcommittee D01.23 on Physical Properties of Applied Paint
Films.
Current edition approved June 1, 2007. Published June 2007. Originally
approved in 1952. Last previous edition approved in 2001 as D1212 - 91 (2001). Both versions of this gage (Interchemical (INMONT) and Model “C”) are
DOI: 10.1520/D1212-91R07E01. covered by U.S. Patents 2 507 592 and 3 128 558 and are issued to Maynard R.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Euverard. Interested parties are invited to submit information regarding the
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM identification of acceptable alternatives to this patented item to the Committee on
Standards volume information, refer to the standard’s Document Summary page on Standards, ASTM Headquarters. Your comments will receive careful consideration
the ASTM website. at a meeting of the responsible technical committee, which you may attend.
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D1212 − 91 (Reapproved2007)
wheel and errors when measuring on uneven support surfaces
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D1212 − 91 (2007)
FIG. 1 Interchemical Wet Film Thickness Gages
FIG. 2 Model “C” Wet Film Thickness Gages
are reduced by placing the eccentric wheel closer to one of the film thickness measurements at least 25 mm (1 in.) from any
supporting concentric wheels.
edge. Determine the film thickness immediately after applica-
tion.
5.3 Best precision is obtained when using the near linear
central portion of each scale, constituting about 80 % of its
6.2 Support the test panels on a suitable level base in such
total range as shown in the diagram in Fig. 1 and Fig. 2.
a way that there will be no movement or spring of the panels
Therefore, the range of the particular gage selected for use
during the film thickness measurements. Place the gage on the
should be such that the measured film thickness falls within,
wet film so that the minimum marking is at the top and the
and preferably toward the center of the middle 80 % of each
greatest clearance between the eccentric wheel and the film is
scale. Gages are available covering the following ranges in
directly over the wet film. Roll the gage over the film one-half
mils and microns:
revolution in one direction toward the minimum marking on
Smallest
Range, mils
the gage and repeat in the opposite direction. Read the points
Graduation, mils
0to2 0.1
at which the coating first makes contact with the eccentric
0to4 0.2
wheel and determine the mean which is considered as one
2to12 0.5
reading.
10 to 30 1.0
20 to 60 2.0
6.3 If the coating contains a solvent that evaporates rapidly
Smallest
Range, µm
Graduation, µm or if the solids content is low, make at least a second separate
0to40 2.0
reading on a freshly applied film and calculate the mean of the
0 to 100 5.00
separate readings.
50 to 250 10.00
200 to 700 25.00
7. Report
6. Procedure
7.1 Report the mean of the separate readings and the range
6.1 ApplythematerialinaccordancewithPracticesD823to
suitable plane rigid panels of area sufficiently large to permit and smallest graduation of the gage used.
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D1212 − 91 (2007)
8. Precision 8.2 The precision of higher range gages is expected to be
proportional to film thickness.
8.1 In an interlaboratory study of this test method, in which
TEST METHOD B
9. Appara
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