ASTM E797/E797M-15

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 reflections can be obtained and resolved.  
1.3 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 may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.4 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-Nov-2015
• ICS: 17.040.20 - Properties of surfaces
• Technical Committee: E07 - Nondestructive Testing
• Drafting Committee: E07.06 - Ultrasonic Method

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E797/E797M − 15
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.
4
1. Scope* 2.2 ASNT Documents:
2 Nondestructive Testing Handbook, 2nd Edition, Vol 7
1.1 This practice provides guidelines for measuring the
SNT-TC-1A Recommended Practice for Personnel Qualifi-
thickness of materials using the contact pulse-echo method at
cation and Certification in Nondestructive Testing
temperatures not to exceed 93°C [200°F].
ANSI/ASNT CP-189 Standard for Qualification and Certifi-
1.2 This practice is applicable to any material in which
cation of Nondestructive Testing Personnel
ultrasonic waves will propagate at a constant velocity through- 5
2.3 Aerospace Industries Association Document:
out the part, and from which back reflections can be obtained
NAS-410 Certification and Qualification of Nondestructive
and resolved.
Testing Personnel
6
1.3 Units—The values stated in either SI units or inch- 2.4 ISO Standard:
pound units are to be regarded separately as standard. The ISO 9712 Non-Destructive Testing—Qualification and Cer-
values stated in each system may not be exact equivalents; tification of NDT Personnel
therefore,eachsystemshallbeusedindependentlyoftheother.
3. Terminology
Combining values from the two systems may result in non-
conformance with the standard.
3.1 Definitions: Definitions—For definitions of terms used
in this practice, refer to Terminology E1316.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Summary of Practice
responsibility of the user of this standard to establish appro-
4.1 Thickness (T), when measured by the pulse-echo ultra-
priate safety and health practices and determine the applica-
sonic method, is a product of the velocity of sound in the
bility of regulatory limitations prior to use.
material and one half the transit time (round trip) through the
2. Referenced Documents material.
3
2.1 ASTM Standards:
Vt
T 5
E317 Practice for Evaluating Performance Characteristics of 2
Ultrasonic Pulse-Echo Testing Instruments and Systems
where:
without the Use of Electronic Measurement Instruments
T = thickness,
E494 Practice for Measuring Ultrasonic Velocity in Materi-
V = velocity, and
als
t = transit time.
E543 Specification for Agencies Performing Nondestructive
4.2 The pulse-echo ultrasonic instrument measures the tran-
Testing
sit time of the ultrasonic pulse through the part.
E1316 Terminology for Nondestructive Examinations
4.3 The velocity in the material being examined is a
function of the physical properties of the material. It is usually
1
This practice is under the jurisdiction of ASTM Committee E07 on Nonde-
assumed to be a constant for a given class of materials. Its
structive Testing and is the direct responsibility of Subcommittee E07.06 on
approximate value can be obtained fromTable X3.1 in Practice
Ultrasonic Method.
Current edition approved Dec. 1, 2015. Published December 2015. Originally
approved in 1981. Last previous edition approved in 2010 as E797 - 10. DOI:
4
10.1520/E0797_E0797M-15. AvailablefromAmericanSocietyforNondestructiveTesting(ASNT),P.O.Box
2
For ASME Boiler and Pressure Vessel Code applications, see related Practice 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
5
SE-797 in Section II of that Code. Available fromAerospace IndustriesAssociation ofAmerica, Inc. (AIA), 1000
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or WilsonBlvd.,Suite1700,Arlington,VA22209-3928,http://www.aia-aerospace.org.
6
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Available from International Organization for Standardization (ISO), ISO
Standards volume information, refer to the standard’s Document Summary page on Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,
the ASTM website. 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

---------------------- Page: 1 ----------------------
E797/E797M − 15
NOTE 1—Slope of velocity conversion line is approximately that of steel.
FIG. 1 Transit Time/Thickness Relationship
E494 or from the Nondestructive Testing Handbook,oritcan 5. Significance and Use
be determined empirically.
5.1 The techniques described provide indirect measurement
of t
...

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 − 10 E797/E797M − 15
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 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].
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 reflections can be obtained and resolved.
1.3 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 may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values
from the two systems may result in non-conformance with the standardstandard.
1.4 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.
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
E543 Specification for Agencies Performing Nondestructive Testing
E1316 Terminology for Nondestructive Examinations
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 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.
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 June 1, 2010Dec. 1, 2015. Published July 2010December 2015. Originally approved in 1981. Last previous edition approved in 20052010 as
E797 - 05.E797 - 10. DOI: 10.1520/E0797_E0797M-10.10.1520/E0797_E0797M-15.
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.
4
Available from American Society for Nondestructive Testing (ASNT), P.O. Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
5
Available from Aerospace Industries Association of America, Inc. (AIA), 1000 Wilson Blvd., Suite 1700, Arlington, VA 22209-3928, http://www.aia-aerospace.org.
6
Available from International Organization for Standardization (ISO), ISO Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier, 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

---------------------- Page: 1 ----------------------
E797/E797M − 15
NOTE 1—Slope of velocity conversion line is approximately that of steel.
FIG. 1 Transit Time/Thickness Relationship
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.
4.2 The pulse-echo ultrasonic instrument measures the transit time of the ultrasonic pulse through the part.
4.3 The velocity in the material bein
...