ASTM E766-98

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E 766 – 98
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Practice for
Calibrating the Magnification of a Scanning Electron
1
Microscope
This standard is issued under the fixed designation E 766; 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.
1. Scope E 691 shall be considered as appropriate to the terms used in
this practice.
1.1 This practice covers general procedures necessary for
3.2 Definitions of Terms Specific to This Standard:
the calibration of magnification of scanning electron micro-
3.2.1 calibration—the set of operations which establish,
scopes. The relationship between true magnification and indi-
under specified conditions, the relationship between magnifi-
cated magnification is a complicated function of operating
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cation values indicated by the SEM and the corresponding
conditions. Therefore, this practice must be applied to each set
magnification values determined by examination of a reference
of standard operating conditions to be used.
material.
1.2 The values stated in SI units are to be regarded as the
3.2.2 calibration method—a technical procedure for per-
standard.
forming a calibration.
1.3 This standard does not purport to address all of the
3.2.3 certified reference material—reference material, ac-
safety concerns, if any, associated with its use. It is the
companied by a certificate, one or more of whose property
responsibility of the user of this standard to establish appro-
values are certified by a procedure which establishes its
priate safety and health practices and determine the applica-
traceability to an accurate realization of the unit in which the
bility of regulatory limitations prior to use.
property values are expressed, and for which each certified
2. Referenced Documents value is accompanied by an uncertainty at a stated level of
confidence (see ISO Guide 30:1992).
2.1 ASTM Standards:
3
3.2.4 pitch—the separation of two similar structures, mea-
E 7 Terminology Relating to Metallography
sured as the center to center or edge to edge distance.
E 29 Standard Practice For Using Significant Digits in Test
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3.2.5 reference standard—a reference material, generally of
Date to Determine Conformance with Specifications
the highest metrological quality available, from which mea-
E 177 Practice for Use of the Terms Precision and Bias in
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surements are derived.
ASTM Test Methods
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3.2.6 reference material—a material or substance one or
E 456 Terminology Relating to Quality and Statistics
more of whose property values are sufficiently homogeneous,
E 691 Practice for Conducting an Interlaboratory Study to
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stable, and well established to be used for the calibration of an
Determine the Precision of a Test Method
apparatus, the assessment of a measurement method, or for
2.2 ISO Standard:
assigning values to materials (see ISO Guide 30:1992).
ISO Guide 30: 1992 Terms and Definitions Used in Con-
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3.2.7 traceability—the property of a result of a measure-
nection with Reference Materials
ment whereby it can be related to appropriate international/
3. Terminology
national standards through an unbroken chain of comparisons.
3.2.8 verification—confirmation by examination and provi-
3.1 Definitions:
sion of evidence that specified requirements have been met.
3.1.1 For definitions of metallographic terms used in this
practice see Terminology E 7.
4. Significance and Use
3.1.2 The definitions related to statistical analysis of date
4.1 Proper use of this practice can yield calibrated magni-
appearing in Practice E 77, Terminology E 456, and Practice
fications with precision of 5 % or better within a magnification
range of from 10 to 50 000X.
1
This practice is under the jurisdiction of ASTM Committee E-4 on Metallog-
4.2 The use of calibration specimens traceable to
raphy and is the direct responsibility of Subcommittee E04.11 on X-Ray and
international/national standards, such as NIST-SRM 484, with
Electron Metallography.
Current edition approved Dec. 10, 1998. Published March 1999. Originally this practice will yield magnifications accurate to better than
published as E 766 – 80. Last previous edition E 766 – 93.
5 % over the calibrated range of operating conditions.
2
See Annex A1.
3 4.3 The accuracy of the calibrated magnifications, or dimen-
Annual Book of ASTM Standards, Vol 03.01.
4
Annual Book of ASTM Standards, Vol 14.02. sional measurements, will be poorer than the accuracy of the
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Available from American National Standards Institute, 11 W. 42nd St., 13th
calibr
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