ASTM D4417-93(1999)
(Test Method)Standard Test Methods for Field Measurement of Surface Profile of Blast Cleaned Steel
Standard Test Methods for Field Measurement of Surface Profile of Blast Cleaned Steel
SCOPE
1.1 These test methods cover the description of techniques for measuring the profile of abrasive blast cleaned surfaces in the laboratory, field, or in the fabricating shop. There are additional techniques suitable for laboratory use not covered by these test methods.
1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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Designation: D 4417 – 93 (Reapproved 1999)
Standard Test Methods for
Field Measurement of Surface Profile of Blast Cleaned
Steel
This standard is issued under the fixed designation D 4417; 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 (e) indicates an editorial change since the last revision or reapproval.
concept of mean maximum profile ( h¯ max); this value is determined by
1. Scope
averaging a given number (usually 20) of the highest peak to lowest valley
1.1 These test methods cover the description of techniques
measurements made in the field of view of a standard measuring
for measuring the profile of abrasive blast cleaned surfaces in
microscope. This is done because of evidence that coatings performance
the laboratory, field, or in the fabricating shop. There are
in any one small area is primarily influenced by the highest surface
additional techniques suitable for laboratory use not covered by features in that area and not by the average roughness.
these test methods.
4. Apparatus
1.2 The values stated in SI units are to be regarded as the
4.1 Method A—A profile comparator consisting of a number
standard. The values given in parentheses are for information
of areas (each approximately one square inch in size), usually
only.
side by side, with a different profile or anchor pattern depth.
1.3 This standard does not purport to address all of the
Each area is marked giving the nominal profile depth in mils or
safety concerns, if any, associated with its use. It is the
micrometres. Typical comparator surfaces are prepared with
responsibility of whoever uses this standard to consult and
steel shot, steel grit, or sand or other nonmetallic abrasive,
establish appropriate safety and health practices and deter-
since the appearance of the profile created by these abrasives
mine the applicability of regulatory limitations prior to use.
may differ. The comparator areas are used with or without
2. Summary of Test Method
magnification of 5 to 10 power.
4.2 Method B—A dial gage depth micrometer fitted with a
2.1 The methods are:
pointed probe. The probe is machined at a 60° angle with a
2.1.1 Method A—The blasted surface is visually compared
nominal radius of 50 μm. The base of the instrument rests on
to standards prepared with various surface profile depths and
the tops of the peaks of the surface profile while the spring
the range determined.
loaded tip projects into the valleys.
2.1.2 Method B—The depth of profile is measured using a
4.3 Method C—A special tape containing a compressible
fine pointed probe at a number of locations and the arithmetic
foam attached to a noncompressible uniform plastic film. A
mean determined.
burnishing tool is used to impress the foam face of the tape into
2.1.3 Method C—A composite plastic tape is impressed into
the surface to create a reverse replica of the profile that is
the blast cleaned surface forming a reverse image of the profile,
measured using a spring-loaded micrometer.
and the maximum peak to valley distance measured with a
micrometer.
5. Test Specimens
3. Significance and Use
5.1 Use any metal surface that, after blast cleaning, is free of
3.1 The height of surface profile has been shown to be a
factor in the performance of various coatings applied to steel.
For this reason, surface profile should be measured prior to
John D. Keane, Joseph A. Bruno, Jr., Raymond E. F. Weaver, “Surface Profile
coating application to ensure that it meets that specified. The
for Anti-Corrosion Paints,” Oct. 25, 1976, Steel Structures Painting Council, 4400
instruments described are readily portable and sufficiently
Fifth Ave., Pittsburgh, PA 15213.
The sole source of supply of suitable depth micrometers known to the
sturdy for use in the field.
committee at this time is the surface profile gage, Model 123, Elcometer Instru-
NOTE 1—Optical microscope methods serve as a referee method for ments, Ltd., Edge Lane, Droylston, Manchester M35 6UB, United Kingdom,
England. If you are aware of alternative suppliers, please proved this information to
surface profile measurement. Profile depth designations are based on the
ASTM Headquarters. Your comments will receive careful consideration at a meeting
of the responsible technical committtee, which you may attend.
1 4
These test methods are under the jurisdiction of ASTM Committee D-1 on Paint The sole source of supply of suitable replica tape, Press-O-Film, known to the
and Related Coatings, Materials, and Applications and are the direct responsibility committee at this time is Testex. 8 Fox Lane, Newark, DE 19711. If you are aware
of Subcommittee D01.46 on Industrial Protective Painting. of alternative suppliers, please proved this information to ASTM Headquarters. Your
Current edition approved May 15, 1993. Published July 1993. Originally comments will receive careful consideration at a meeting of the responsible
published as D 4417 – 84. Last previous edition D 4417 – 84. technical committtee, which you may attend
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 4417
loose surface interference material, dirt, dust, and abrasive sured, and the approximate total area covered.
residue.
8. Precision and Bias
6. Procedure
8.1 Test Method A:
8.1.1 Applicability—Based on measurements of profiles on
6.1 Method A:
surfaces of 8 steel panels, each blast cleaned with 1 of 8
6.1.1 Select the comparator standard appropriate for the
different abrasives to a white metal degree of cleaning, having
abrasive used for blast cleaning.
known ratings of profile height ranging from 37 μm (1.5 mils)
6.1.2 Place the comparator standard directly on the surface
to be measured and compare the roughness of the prepared to 135 μm (5.4 mils), the correlation coefficient for Test
Method A was found to be 0.75 and the coefficient of
surface with the roughness on the comparator segments. This
can be done with the unaided eye, under 5 to 10 power determination was found to be 0.54.
8.1.2 Precision—In an interlaboratory study of Test Method
magnification, or by touch. When using magnification, the
A in which 2 operators each running 2 tests on separate days in
magnifier should be brought into intimate contact with the
each of 6 laboratories tested 8 surfaces with a broad range of
standard, and the depth of focus must be sufficient for the
profile characteristics and levels, the intralaboratory coefficient
standard and surface to be in focus simultaneously.
of variation was found to be 20 % with 141 df and the
6.1.3 Select the comparator segment that most closely
interlaboratory coefficient was found to be 19 % with 40 df,
approximates the roughness of the surface being evaluated or,
after rejecting 3 results for one time because the range between
if necessary, the two segments to which it is intermediate.
repeats differed significantly from all other ranges. Based on
6.1.4 Evaluate the roughness at a sufficient number of
these coefficients, the following criteria should be used for
locations to characterize the surface as specified or agreed upon
judging, at the 95 % confidence level, the acceptability of
between the interested parties. Report the range of results from
results:
all locations as the surface profile.
8.1.2.1 Repeatability—Two results, each the mean of four
6.2 Method B:
replicates, obtained by the same operator should be considered
6.2.1 Prior to use set the gage to zero by placing it on a piece
suspect if they differ by more than 56 %.
of plate float glass. Hold the gage by its base and press firmly
8.1.2.2 Reproducibility—Two results, each the mean of four
against the glass. Adjust the instrument to zero.
replicates, obtained by operators in different laboratories
6.2.2 To take readings, hold the gage firmly against the
prepared substrate. Do not drag the instrument across the should be considered susp
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