ASTM E1629-07

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Designation: E1629 − 07
StandardPractice for
Determining the Impedance of Absolute Eddy-Current
1
Probes
This standard is issued under the fixed designation E1629; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
3.1 Definitions—The terminology relating to eddy-current
1.1 This practice covers a procedure for determining the
examination that appears in Terminology E1316 shall apply to
impedance of absolute eddy-current probes (bridge-type, air or
the terms used in this practice.
ferrite core, wire wound, shielded, or unshielded) used for
3.2 Definitions of Terms Specific to This Standard:
finding material defects in electrically conducting material.
3.2.1 eddy-current test block— for the purposes of the
This practice is intended to establish a uniform test methodol-
method described in this practice, a rectangular block made of
ogy to measure the impedance of eddy-current probes prior to
an aluminum alloy (see 6.1.2) to which an active eddy-current
receipt of these probes by the purchaser or the specifier.
probe is applied.
1.2 Limitations—This practice does not address the charac-
3.3 Mathematical Symbols:
terization or measurement of the impedance of differential, a-c
3.3.1 j—asymbolusedinelectricalengineeringtorepresent
coupled,ortransmit/receivetypesofprobes.Thispracticedoes
=21 . It is associated with the restriction to the flow of
not address the use of magnetic materials in testing probes.
electrical current caused by capacitors and coils.
This practice shall not be used as a basis for selection of the
best probe for a particular application or as a means by which
3.3.2 N— any number.
to calibrate a probe for a specific examination.
3.3.3 | –N|—the magnitude of N, regardless whether N is
positive, negative, or a vector quantity.
1.3 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information 3.3.4 =N— the square root of N.
only.
2
3.3.5 (–N) —N squared, that is, N× N.
1.4 This standard does not purport to address all of the
3.3.6 ∆N— delta N, the change or difference in N.
safety concerns, if any, associated with its use. It is the
3.4 Abbreviations:
−1
responsibility of the user of this standard to establish appro-
3.4.1 tan—used for the tangent function. The tan , arc
priate safety and health practices and determine the applica-
tangent or inverse tangent function, returns a value that is a
bility of regulatory limitations prior to use.
measure of an angle and can be in either degrees or radians.
−1
When using a calculator to determine the tan , care should be
2. Referenced Documents
taken to determine whether the answer is in degrees or radians
since the numerical values that represent the same angle are
2.1 The following document forms a part of this practice to
different.
the extent specified herein:
3.4.2 cos—used for the cosine function.
2.2 ASTM Standards:
2
3.4.3 sin—used for the sine function.
E1316Terminology for Nondestructive Examinations
4. Significance and Use
1
This practice is under the jurisdiction of ASTM Committee E07 on Nonde-
4.1 Eddy-currentprobesmaybeusedforthenondestructive
structive Testing and is the direct responsibility of Subcommittee E07.07 on
examinationofpartsorstructuresmadeofelectricallyconduct-
Electromagnetic Method.
ing materials. Many of these examinations are intended to
CurrenteditionapprovedJuly1,2007.PublishedJuly2007.Originallyapproved
discover material defects, such as cracks, that may cause the
in 1994. Last previous edition approved in 2001 as E1629-94(2001). DOI:
10.1520/E1629-07.
part or structure to be unsafe or unfit for service. Eddy-current
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
probes that fail to meet the performance level requirements of
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
this practice shall not be used for the examination of material
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. orhardwareunlesstheprobeisqualifiedbysomeothersystem
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E1629 − 07
or an agreement has been reached by the probe manufacturer This instrument shall be certified as having been calibrated in
and the purchaser, or both. accordance with the manufacturer’s specifications, with the
calibration sticker indicating the calibration date and the
5. General Practice
required interval or next calibration date.
6.1.2
...