ASTM E252-06(2013)

Standard Test Method for Thickness of Foil, Thin Sheet, and Film by Mass Measurement

ABSTRACT
This test method covers the standard procedures for the determination of the thickness of metallic foils, thin sheets, and films by measuring the mass of the specimen of known area and density. The apparatuses needed for this method are a precision blanking press for cutting specimens into circles of a specified area or diameter, and a balance for measuring its mass. The thickness shall then be calculated by using an equation that relates it with the specimen's mass, area, and density.
SCOPE
1.1 This test method covers the determination of the thickness of metallic foil and sheet 0.015 in. (0.38 mm) and less in thickness by measuring the mass of a specimen of known area and density. The test method is applicable to other sheet, foil, and film as indicated in Annex A3.  
1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units, which are provided for information only and are not considered standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Sep-2013
• ICS: 17.040.20 - Properties of surfaces
• Technical Committee: B07 - Light Metals and Alloys
• Drafting Committee: B07.05 - Testing

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E252 − 06 (Reapproved 2013)
Standard Test Method for
Thickness of Foil, Thin Sheet, and Film by Mass
Measurement
This standard is issued under the fixed designation E252; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope* specimens may be used with the recognition that the accuracy
stated in 6.1 is no longer applicable. See Annex A1 for the
1.1 This test method covers the determination of the thick-
selection of other specimen sizes and the resulting change in
ness of metallic foil and sheet 0.015 in. (0.38 mm) and less in
accuracy of the test method.
thickness by measuring the mass of a specimen of known area
and density. The test method is applicable to other sheet, foil, 3.2 Balance—capable of measuring to the nearest 0.1 mg of
2 2
and film as indicated in Annex A3. thickness for the 8.000-in. (51.613-cm ) circle.
1.2 The values stated in inch-pound units are to be regarded
4. Procedure
asthestandard.Thevaluesgiveninparenthesesaremathemati-
2 2
4.1 Blank an 8.000 6 0.008-in. (51.613 6 0.051-cm )
cal conversions to SI units, which are provided for information
circle representative of the foil or sheet, swab with acetone or
only and are not considered standard.
other suitable solvent to ensure a surface free of soil, and
1.3 This standard does not purport to address all of the
determine the mass of the clean, dry specimen to the nearest
safety concerns, if any, associated with its use. It is the
0.1 mg. Use a suitable solvent to remove any coating known to
responsibility of the user of this standard to establish appro- 2 2
exceed 0.005 mg/ft (4.645 mg/cm ) of surface area.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
5. Calculation
5.1 Determine the thickness from the relationship:
2. Referenced Documents
M
2.1 The following documents of the issue in effect on the
T 5
A·D
date of material purchase, unless otherwise noted, form a part
of this specification to the extent referenced herein:
where:
T = thickness of the foil, sheet, or film, in. (or cm),
2.2 ASTM Standards:
M = mass of the circle, g,
D1505 Test Method for Density of Plastics by the Density-
2 2
A = area of the circle, in. (or cm ), and
Gradient Technique
3 3
D = density of the foil, sheet, or film, g/in. (or Mg/m ).
E29 Practice for Using Significant Digits in Test Data to
Determine Conformance with Specifications
5.2 Densities of Aluminum Alloys:
5.2.1 Calculate the density of aluminum foil or sheet from
3. Apparatus
chemical composition limits of the alloy by the method
described in Annex A2. The densities of foil or sheet alloys
3.1 Precision Blanking Press—to cut foil or sheet circles
2 2
determined in this manner are accurate to within 6 0.3 %.
that are 8.000 6 0.008 in. (51.613 6 0.051 cm ) in area or
5.2.2 Calculated densities for some of the common foil or
3.1915 60.0015in.(81.06 60.04mm)indiameter.Othersize
sheet alloys can be found in Table 1.Acolumn headed “mils/g
for 8.000-in. Area” is added for convenience in determining
2 2
This test method is under the jurisdiction of ASTM Committee B07 on Light
thickness of the 8.000-in. (51.613-cm ) specimens. The mass
Metals and Alloys and is the direct responsibility of Subcommittee B07.05 on
of the specimen in grams multiplied by this factor is equal to
Testing.
the thickness of the foil or sheet in mils. One mil is equal to
Current edition approved Oct. 1, 2013. Published October 2013. Originally
0.001 in. (0.0254 mm).
approved in 1964. Last previous edition approved in 2006 as E252 – 06. DOI:
10.1520/E0252-06R13.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 6. Precision and Bias
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
6.1 Following the procedure outlined in this test method,
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. repeatedmassmeasurementsofthesamespecimenondifferent
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E252 − 06 (2013)
TABLE 1 Densities of Aluminum Foil or Sheet Alloys Applicable
to the Determination of Thickness by the Mass Measurement
Method
Density
mils/g for 8.000-in.
Alloy
3 3A
Area
g/in. Mg/m
1100 44.41 2.71 2.815
1145 44.24 2.700 2.826
1188 44.24 2.700 2.826
1199 44.24 2.700 2.826
1235 44.33 2.705 2.820
3003 44.74 2.73 2.794
5052 43.92 2.68 2.846
5056 43.26 2.64 2.890
8079 44.57 2.72 2.805
8111 44.41 2.71 2.815
A
Registration Record of Aluminum Association Designations and Chemical Com-
position Limits for Wrought Aluminum and Wrought Aluminum Alloys, Aluminum
Assoc., Washington, DC.
balances should result in agreement within 1 mg. It is outside
of the scope of this test method to describe maintenance and
calibration procedures for balances, but disagreement larger
than 1 mg warrants attention to maintenance or recalibration of
the balance.
ANNEXES
(Mandatory Information)
A1. SPECIMEN SIZE AND SHAPE AND ITS EFFECT ON ACCURACY
A1.1 General 6 0.3 % of the true density. The error imposed by uncertainty
of the density then is E = 6 0.3 % of the thickness deter-
D
A1.1.1 Specimens of sizes and shapes other than the 8.000-
mined.
2 2
in. (51.613-cm ) circle maybe used provided consideration is
given to controllable factors affecting the accuracy of the
A1.4 Error from Control of the Area of the Specimen (E )
A
method. Specifically, the area of the specimen shall be known
A1.4.1 Aprecisionblankingpresscancutaspecimenwhose
and controlled to an accuracy of 60.1 %, and the minimum
area is known and reproducible to an accuracy of 60.1 %. If d
mass of the specimen shall be 70 mg. Specimens ranging in
2 2
is the specific diameter required to provide the area used in the
size from 8 to 32 in. (52 to 206 cm ) are convenient to handle
thickness computation, then the error in area resulting from a
and can be prepared to meet the aforementioned requirements.
small error,∆d, in the diameter is 200∆d/d %. It follows then
A1.2 Source of Error
that to maintain an area accurate to 60.1 %, the tolerance on
the diameter of the blanked circle shall be 60.0005 times the
A1.2.1 Inherent errors in determining thickness by the mass
circle diameter. The fact that the tolerance on diameter de-
measurement method result from the limits on the accuracy of
creases in direct proportion to the diameter is a factor to
thedensityvalueassignedtothealloy,theaccuracywithwhich
consider in selecting the specimen size to use in the method.
a specimen can be cut and its area determined, and the
Compliance with this tolerance limits the area error to
accuracy of the mass measurement. Much time could be
E = 6 0.1 % of the thickness determined.
devoted to a discussion of refinement of errors but it shall A
suffice here to draw on experience as a guide for determining
A1.5 Error from Measuring the Mass of the Specimen
the accuracy of the method.
(E )
M
A1.3 Error from Uncertainty of the Densities of the Speci-
A1.5.1 The accuracy of measuring the mass of a foil or
men (E )
D
sheet specimen has been found to be 0.7 mg. This imposes a
A1.3.1 The density of aluminum foil or sheet alloys shall be maximum error on the method of 6 0.07/(T·A·D) % of the
those listed in Table 1 or it shall be determined by the method thickness determined. Since D, density of the foil or sheet, is
described in Annex A2. Values so obtained are accurate to fixed, it is seen that the magnitude of the mass measurement
E252 − 06 (2013)
error is a function of the thickness, T, of the foil or sheet and maximumerrorofthemethodis (E +E +E )percentofthe
D A M
the area, A, of the specimen. The area, A, is a controllable thickness determined. Since these errors at a given test location
factor in the method, and the importance of selecting a large
are normally in the nature of a bias rather than random error,
area to minimize the overall percentage error in the method for
the accuracy of the method is best described in terms of this
thin foil or sheet is apparent from a few simple calculations.
maximum error. The maximum er
...