ASTM E797/E797M-21

Standard Practice for Measuring Thickness by Manual Ultrasonic Pulse-Echo Contact Method

SIGNIFICANCE AND USE
5.1 The techniques described provide indirect measurement of thickness of sections of materials not exceeding temperatures of 93 °C [200 °F]. Measurements are made from one side of the object, without requiring access to the rear surface.  
5.2 Ultrasonic thickness measurements are used extensively on basic shapes and products of many materials, on precision machined parts, and to determine wall thinning in process equipment caused by corrosion and erosion.  
5.3 Recommendations for determining the capabilities and limitations of ultrasonic thickness gages for specific applications can be found in the cited references.7,8
SCOPE
1.1 This practice2 provides guidelines for measuring the thickness of materials using the contact pulse-echo method at temperatures not to exceed 93 °C [200 °F].  
1.2 This practice is applicable to any material in which ultrasonic waves will propagate at a constant velocity throughout the part, and from which back wall reflections can be obtained and resolved.  
1.3 This practice is primarily for flat components with parallel surfaces and has limited applicability for components with non-parallel or concentric surfaces per 1.2.  
1.4 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.  
1.5 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.  
1.6 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.

General Information

• Status: Published
• Publication Date: 31-May-2021
• ICS: 17.040.20 - Properties of surfaces
• Technical Committee: E07 - Nondestructive Testing
• Drafting Committee: E07.06 - Ultrasonic Method

Standards Content (Sample)

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.
Designation: E797/E797M − 21
Standard Practice for
Measuring Thickness by Manual Ultrasonic Pulse-Echo
1
Contact Method
This standard is issued under the fixed designation E797/E797M; 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* 2. Referenced Documents
2
3
1.1 This practice provides guidelines for measuring the 2.1 ASTM Standards:
thickness of materials using the contact pulse-echo method at
E317 Practice for Evaluating Performance Characteristics of
temperatures not to exceed 93 °C [200 °F].
Ultrasonic Pulse-Echo Testing Instruments and Systems
without the Use of Electronic Measurement Instruments
1.2 This practice is applicable to any material in which
E494 Practice for Measuring Ultrasonic Velocity in Materi-
ultrasonic waves will propagate at a constant velocity through-
als by Comparative Pulse-Echo Method
out the part, and from which back wall reflections can be
E543 Specification for Agencies Performing Nondestructive
obtained and resolved.
Testing
1.3 This practice is primarily for flat components with
E1316 Terminology for Nondestructive Examinations
parallel surfaces and has limited applicability for components
4
2.2 ASNT Documents:
with non-parallel or concentric surfaces per 1.2.
Nondestructive Testing Handbook, 2nd Edition, Vol 7
1.4 Units—The values stated in either SI units or inch- SNT-TC-1A Recommended Practice for Personnel Qualifi-
pound units are to be regarded separately as standard. The cation and Certification in Nondestructive Testing
values stated in each system are not necessarily exact equiva- ANSI/ASNT CP-189 Standard for Qualification and Certifi-
lents; therefore, to ensure conformance with the standard, each cation of Nondestructive Testing Personnel
system shall be used independently of the other, and values 5
2.3 AIA Document:
from the two systems shall not be combined.
NAS-410 Certification and Qualification of Nondestructive
1.5 This standard does not purport to address all of the Testing Personnel
6
safety concerns, if any, associated with its use. It is the
2.4 ISO Standard:
responsibility of the user of this standard to establish appro-
ISO 9712 Non-Destructive Testing—Qualification and Cer-
priate safety, health, and environmental practices and deter-
tification of NDT Personnel
mine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accor-
3. Terminology
dance with internationally recognized principles on standard-
3.1 Definitions—For definitions of terms used in this
ization established in the Decision on Principles for the
practice, refer to Terminology E1316.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
1
This practice is under the jurisdiction of ASTM Committee E07 on Nonde- the ASTM website.
4
structive Testing and is the direct responsibility of Subcommittee E07.06 on AvailablefromAmericanSocietyforNondestructiveTesting(ASNT),P.O.Box
Ultrasonic Method. 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
5
Current edition approved June 1, 2021. Published September 2021. Originally Available fromAerospace IndustriesAssociation ofAmerica, Inc. (AIA), 1000
approved in 1981. Last previous edition approved in 2015 as E797/E797M – 15. WilsonBlvd.,Suite1700,Arlington,VA22209-3928,http://www.aia-aerospace.org.
6
DOI: 10.1520/E0797_E0797M-21. Available from International Organization for Standardization (ISO), ISO
2
For ASME Boiler and Pressure Vessel Code applications, see related Practice Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,
SE-797 in Section II of that Code. Geneva, Switzerland, http://www.iso.org.
*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

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E797/E797M − 21
NOTE 1—Slope of velocity conversion line is approximately that of steel.
FIG. 1 Transit Time/Thickness Relationship
4. Summary of Practice values. One block should have a thickness value near the
maximum of the rang
...

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: E797/E797M − 15 E797/E797M − 21
Standard Practice for
Measuring Thickness by Manual Ultrasonic Pulse-Echo
1
Contact Method
This standard is issued under the fixed designation E797/E797M; 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*
2
1.1 This practice provides guidelines for measuring the thickness of materials using the contact pulse-echo method at
temperatures not to exceed 93°C [200°F].93 °C [200 °F].
1.2 This practice is applicable to any material in which ultrasonic waves will propagate at a constant velocity throughout the part,
and from which back wall reflections can be obtained and resolved.
1.3 This practice is primarily for flat components with parallel surfaces and has limited applicability for components with
non-parallel or concentric surfaces per 1.2.
1.4 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
standard.shall not be combined.
1.5 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.
1.6 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
3
2.1 ASTM Standards:
E317 Practice for Evaluating Performance Characteristics of Ultrasonic Pulse-Echo Testing Instruments and Systems without the
Use of Electronic Measurement Instruments
E494 Practice for Measuring Ultrasonic Velocity in Materials by Comparative Pulse-Echo Method
E543 Specification for Agencies Performing Nondestructive Testing
E1316 Terminology for Nondestructive Examinations
1
This practice is under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.06 on Ultrasonic Method.
Current edition approved Dec. 1, 2015June 1, 2021. Published December 2015September 2021. Originally approved in 1981. Last previous edition approved in 20102015
as E797 - 10.E797/E797M – 15. DOI: 10.1520/E0797_E0797M-15.10.1520/E0797_E0797M-21.
2
For ASME Boiler and Pressure Vessel Code applications, see related Practice SE-797 in Section II of that Code.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on 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
1

---------------------- Page: 1 ----------------------
E797/E797M − 21
4
2.2 ASNT Documents:
Nondestructive Testing Handbook, 2nd Edition, Vol 7
SNT-TC-1A Recommended Practice for Personnel Qualification and Certification in Nondestructive Testing
ANSI/ASNT CP-189 Standard for Qualification and Certification of Nondestructive Testing Personnel
5
2.3 Aerospace Industries Association AIA Document:
NAS-410 Certification and Qualification of Nondestructive Testing Personnel
6
2.4 ISO Standard:
ISO 9712 Non-Destructive Testing—Qualification and Certification of NDT Personnel
3. Terminology
3.1 Definitions: Definitions—For definitions of terms used in this practice, refer to Terminology E1316.
3.1 Definitions—For definitions of terms used in this practice, refer to Terminology E1316.
4. Summary of Practice
4.1 Thickness (T), when measured by the pulse-echo ultrasonic method, is a product of the velocity of sound in the material and
one half the transit time (round trip) through the material.
Vt
T 5
2
where:
T = thickness,
V = velocity, and
t = transit time.
T = Component t
...