ASTM E1781/E1781M-19
(Practice)Standard Practice for Secondary Calibration of Acoustic Emission Sensors
Standard Practice for Secondary Calibration of Acoustic Emission Sensors
SIGNIFICANCE AND USE
4.1 The purpose of this practice is to enable the transfer of calibration from sensors that have been calibrated by primary calibration to other sensors.
SCOPE
1.1 This practice covers requirements for the secondary calibration of acoustic emission (AE) sensors. The secondary calibration yields the frequency response of a sensor to waves of the type normally encountered in acoustic emission work. The source producing the signal used for the calibration is mounted on the same surface of the test block as the sensor under testing (SUT). Rayleigh waves are dominant under these conditions; the calibration results represent primarily the sensor's sensitivity to Rayleigh waves. The sensitivity of the sensor is determined for excitation within the range of 100 kHz to 1 MHz. Sensitivity values are usually determined at frequencies approximately 10 kHz apart. The units of the calibration are volts per unit of mechanical input (displacement, velocity, or acceleration).
1.2 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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Designation: E1781/E1781M − 19
Standard Practice for
1
Secondary Calibration of Acoustic Emission Sensors
ThisstandardisissuedunderthefixeddesignationE1781/E1781M;thenumberimmediatelyfollowingthedesignationindicatestheyear
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* 2. Referenced Documents
2
1.1 This practice covers requirements for the secondary 2.1 ASTM Standards:
calibration of acoustic emission (AE) sensors. The secondary E114 Practice for Ultrasonic Pulse-Echo Straight-Beam
calibration yields the frequency response of a sensor to waves Contact Testing
of the type normally encountered in acoustic emission work. E494Practice for Measuring Ultrasonic Velocity in Materi-
The source producing the signal used for the calibration is als
mounted on the same surface of the test block as the sensor E1106Test Method for Primary Calibration of Acoustic
undertesting(SUT).Rayleighwavesaredominantunderthese Emission Sensors
conditions; the calibration results represent primarily the sen- E1316Terminology for Nondestructive Examinations
sor’s sensitivity to Rayleigh waves. The sensitivity of the
3. Terminology
sensorisdeterminedforexcitationwithintherangeof100kHz
3.1 Definitions—Refer to Terminology E1316, Section B,
to1MHz.Sensitivityvaluesareusuallydeterminedatfrequen-
for terms used in this practice.
cies approximately 10 kHz apart. The units of the calibration
3.2 Definitions of Terms Specific to This Standard:
are volts per unit of mechanical input (displacement, velocity,
3.2.1 reference sensor (RS), n—a sensor that has had its
or acceleration).
response established by primary calibration (also called sec-
1.2 Units—The values stated in either SI units or inch-
ondary standard transducer) (see Test Method E1106).
pound units are to be regarded separately as standard. The
values stated in each system are not necessarily exact equiva-
3.2.1.1 Discussion—Alternatively, a sensor calibrated by a
lents; therefore, to ensure conformance with the standard, each laser interferometer or similar device may be used as a
system shall be used independently of the other, and values
reference standard.
from the two systems shall not be combined.
3.2.2 secondary calibration, n—a procedure for measuring
the frequency or transient response of an AE sensor by
1.3 This standard does not purport to address all of the
comparison with an RS.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 3.2.3 test block, n—a block of homogeneous, isotropic,
priate safety, health, and environmental practices and deter-
elastic material on which a source, an RS, and a SUT are
mine the applicability of regulatory limitations prior to use. placed for conducting secondary calibration.
1.4 This international standard was developed in accor-
4. Significance and Use
dance with internationally recognized principles on standard-
4.1 The purpose of this practice is to enable the transfer of
ization established in the Decision on Principles for the
calibration from sensors that have been calibrated by primary
Development of International Standards, Guides and Recom-
calibration to other sensors.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
5. General Requirements
5.1 Units for Calibration—Secondary calibration produces
the same type of information regarding a sensor as does
1
This practice is under the jurisdiction of ASTM Committee E07 on Nonde-
structive Testing and is the direct responsibility of Subcommittee E07.04 on
2
Acoustic Emission Method. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved July 1, 2019. Published August 2019. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1996. Last previous edition approved in 2013 as E1781/E1781M–13. Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/E1781_E1781M-19. the ASTM website.
*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
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E1781/E1781M − 19
primary calibration (Test Method E1106). An AE sensor
respondstomotionatitsfrontface.Theactualstressandstrain
atthefrontfaceofamountedsensordependsontheinteraction
between the mechanical impedance of the sensor (load) and
that of the mounting block (driver); neither the stress nor the
strain is amenable to direct measurement at this location.
However,thefreedisplacementtha
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E1781/E1781M − 13 E1781/E1781M − 19
Standard Practice for
1
Secondary Calibration of Acoustic Emission Sensors
This standard is issued under the fixed designation E1781/E1781M; 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.
1. Scope*
1.1 This practice covers requirements for the secondary calibration of acoustic emission (AE) sensors. The secondary
calibration yields the frequency response of a sensor to waves of the type normally encountered in acoustic emission work. The
source producing the signal used for the calibration is mounted on the same surface of the test block as the sensor under testing
(SUT). Rayleigh waves are dominant under these conditions; the calibration results represent primarily the sensor’s sensitivity to
Rayleigh waves. The sensitivity of the sensor is determined for excitation within the range of 100 kHz to 1 MHz. Sensitivity values
are usually determined at frequencies approximately 10 kHz apart. The units of the calibration are volts per unit of mechanical
input (displacement, velocity, or acceleration).
1.2 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated
in each system mayare not benecessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall
be used independently of the other. Combiningother, and values from the two systems may result in non-conformance with the
standards.shall not be combined.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
E114 Practice for Ultrasonic Pulse-Echo Straight-Beam Contact Testing
E494 Practice for Measuring Ultrasonic Velocity in Materials
E1106 Test Method for Primary Calibration of Acoustic Emission Sensors
E1316 Terminology for Nondestructive Examinations
3. Terminology
3.1 Definitions—Refer to Terminology E1316, Section B, for terms used in this practice.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 reference sensor (RS)—(RS), n—a sensor that has had its response established by primary calibration (also called
secondary standard transducer) (see Test Method E1106).
1
This practice is under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.04 on Acoustic Emission
Method.
Current edition approved June 1, 2013July 1, 2019. Published June 2013August 2019. Originally approved in 1996. Last previous edition approved in 20082013 as
E1781 - 08.E1781/E1781M – 13. DOI: 10.1520/E1781_E1781M-13.10.1520/E1781_E1781M-19.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3.2.1.1 Discussion—
Alternatively, a sensor calibrated by a laser interferometer or similar device may be used as a reference standard.
3.2.2 secondary calibration—calibration, n—a procedure for measuring the frequency or transient response of an AE sensor by
comparison with an RS.
*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
1
---------------------- Page: 1 ----------------------
E1781/E1781M − 19
FIG. 1 Schematic of the Prototype Secondary Calibration Apparatus: A = a Capillary-Break Source, B = a 41 by 41 by 19-cm19 cm [16
by 16 by 7.5 in.] Steel Block, C = the RS, D = the SUT, and E = the Two-Channel Waveform Recorder System
3.2.3 test block—block, n—a block of homogeneous, isotropic, elastic material on which a source, an RS, and a SUT are placed
...
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