ASTM E797-05

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

SIGNIFICANCE AND USE
The techniques described provide indirect measurement of thickness of sections of materials not exceeding temperatures of 200°F [93°C]. Measurements are made from one side of the object, without requiring access to the rear surface.
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.
Recommendations for determining the capabilities and limitations of ultrasonic thickness gages for specific applications can be found in the cited references.5 ,6
SCOPE
1.1 This practice² provides guidelines for measuring the thickness of materials using the contact pulse-echo method at temperatures not to exceed 200°F [93°C].
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 The values stated in either inch-pound or SI units are to be regarded as standard. The values given in brackets are for information only.
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-2005
• ICS: 19.100 - Non-destructive testing
• Technical Committee: E07 - Nondestructive Testing
• Drafting Committee: E07.06 - Ultrasonic Method

Relations

• Replaces: ASTM E797-95(2001) - Standard Practice for Measuring Thickness by Manual Ultrasonic Pulse-Echo Contact Method
• Effective Date: 01-Dec-2005
• Replaced By: ASTM E797/E797M-10 - Standard Practice for Measuring Thickness by Manual Ultrasonic Pulse-Echo Contact Method
• Effective Date: 01-Jun-2010
• Referred By: ASTM E494-20 - Standard Practice for Measuring Ultrasonic Velocity in Materials by Comparative Pulse-Echo Method
• Effective Date: 01-Dec-2005
• Referred By: ASTM E543-21 - Standard Specification for Agencies Performing Nondestructive Testing
• Effective Date: 01-Dec-2005
• Referred By: ASTM F1743-22 - Standard Practice for Rehabilitation of Existing Pipelines and Conduits by Pulled-in-Place Installation of Cured-in-Place Thermosetting Resin Pipe (CIPP)
• Effective Date: 01-Dec-2005
• Referred By: ASTM E1816-18(2022) - Standard Practice for Measuring thickness by Pulse-Echo Electromagnetic Acoustic Transducer (EMAT) Methods
• Effective Date: 01-Dec-2005

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:E797–05
Standard Practice for
Measuring Thickness by Manual Ultrasonic Pulse-Echo
1
Contact Method
This standard is issued under the fixed designation E797; 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 4. Summary of Practice
2
4.1 Thickness (T), when measured by the pulse-echo ultra-
1.1 This practice provides guidelines for measuring the
thickness of materials using the contact pulse-echo method at sonic method, is a product of the velocity of sound in the
temperatures not to exceed 200°F [93°C]. material and one half the transit time (round trip) through the
1.2 This practice is applicable to any material in which material.
ultrasonic waves will propagate at a constant velocity through-
Vt
T 5
out the part, and from which back reflections can be obtained
2
and resolved.
where:
1.3 The values stated in either inch-pound or SI units are to
T = thickness,
be regarded as standard. The values given in brackets are for
V = velocity, and
information only.
t = transit time.
1.4 This standard does not purport to address all of the
4.2 The pulse-echo ultrasonic instrument measures the tran-
safety concerns, if any, associated with its use. It is the
sit time of the ultrasonic pulse through the part.
responsibility of the user of this standard to establish appro-
4.3 The velocity in the material being examined is a
priate safety and health practices and determine the applica-
function of the physical properties of the material. It is usually
bility of regulatory limitations prior to use.
assumed to be a constant for a given class of materials. Its
approximate value can be obtained fromTable X3.1 in Practice
2. Referenced Documents
3
E494 or from the Nondestructive Testing Handbook,oritcan
2.1 ASTM Standards:
be determined empirically.
E317 Practice for Evaluating Performance Characteristics
4.4 One or more reference blocks are required having
of Ultrasonic Pulse-Echo Testing Instruments and Systems
known velocity, or of the same material to be examined, and
without the Use of Electronic Measurement Instruments
having thicknesses accurately measured and in the range of
E494 Practice for Measuring Ultrasonic Velocity in Mate-
thicknesses to be measured. It is generally desirable that the
rials
thicknesses be “round numbers” rather than miscellaneous odd
E1316 Terminology for Nondestructive Examinations
values. One block should have a thickness value near the
2.2 ASNT Document:
4
maximum of the range of interest and another block near the
Nondestructive Testing Handbook, 2nd Edition, Vol 7
minimum thickness.
3. Terminology
4.5 The display element (A-scan display, meter, or digital
display) of the instrument must be adjusted to present conve-
3.1 Definitions—For definitions of terms used in this
nient values of thickness dependent on the range being used.
practice, refer to Terminology E1316.
The control for this function may have different names on
different instruments, including range, sweep, material stan-
1
This practice is under the jurisdiction of ASTM Committee E07 on Nonde-
dardize,or velocity.
structive Testing and is the direct responsibility of Subcommittee E07.06 on
4.6 The timing circuits in different instruments use various
Ultrasonic Testing Procedure.
Current edition approved Dec. 1, 2005. Published December 2005. Originally
conversion schemes. A common method is the so-called
approved in 1981. Last previous edition approved in 2001 as E797 - 95(2001). DOI:
time/analog conversion in which the time measured by the
10.1520/E0797-05.
2
instrumentisconvertedintoaproportionald-cvoltagewhichis
For ASME Boiler and Pressure Vessel Code applications, see related Practice
SE-797 in Section II of that Code. then applied to the readout device. Another technique uses a
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
veryhigh-frequencyoscillatorthatismodulatedorgatedbythe
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
appropriate echo indications, the output being used either
Standards volume information, refer to the standard’s Document Summary page on
directlytosuitabledigitalreadoutsorconvertedtoavoltagefor
the ASTM website.
4
AvailablefromAmericanSocietyforNondestructiveTesting(ASNT),P.O.Box
28518, 1711 Arlingate Ln., Columbus, OH 43228-0518.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
E797–05
NOTE 1—Slope of velocity conversion line is approximately that of steel.
FIG. 1 Transit Time/Thickness Relat
...

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:E 797–95 (Reapproved 2001) Designation:E797–05
Standard Practice for
Measuring Thickness by Manual Ultrasonic Pulse-Echo
1
Contact Method
This standard is issued under the fixed designation E797; 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 200°F (93°C). [93°C].
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 Thevaluesstatedineitherinch-poundorSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesbrackets
are for information only.
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 Examination Testing Instruments and
Systems Withoutwithout the Use of Electronic Measurement Instruments
E494 Practice for Measuring Ultrasonic Velocity in Materials
E1316 Terminology for Nondestructive Examinations
2.2 ASNT Document:
4
Nondestructive Testing Handbook, 2nd Edition, Vol 7
3. Terminology
3.1 Definitions—For definitions of terms used in this practice, refer to Terminology E 1316E1316.
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.
T 5 Vt2
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 being examined is a function of the physical properties of the material. It is usually assumed
to be a constant for a given class of materials. Its approximate value can be obtained from Table X3.1 in Practice E 494E494 or
from the Nondestructive Testing Handbook, or it can be determined empirically.
1
This practice is under the jurisdiction ofASTM Committee E07 on NondestructiveTesting and is the direct responsibility of Subcommittee E07.06 on UltrasonicTesting
Procedure.
Current edition approved Dec. 10, 1995. Published February 1996. Originally published as E 797–81. Last previous edition E 797–94.
Current edition approved Dec. 1, 2005. Published December 2005. Originally approved in 1981. Last previous edition approved in 2001 as E797 - 95(2001). DOI:
10.1520/E0797-05.
2
For ASME Boiler and Pressure Vessel Code applications, see related Practice SE-797 in Section II of that Code.
3
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
, Vol 03.03.volume information, refer to the standard’s Document Summary page on the ASTM website.
4
Available from the American Society for Nondestructive Testing, 1711 Arlingate Plaza, Columbus, OH 43228.
4
Available from American Society for Nondestructive Testing (ASNT), P.O. Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
E797–05
4.4 One or more reference blocks are required having known velocity, or of the same material to be examined, and having
thicknesses accurately measured and in the range of thicknesses to be measured. It is generally desirable that the thicknesses be
“round numbers” rather than miscellaneous odd values. One block should have a thickness value near the maximum of the range
of interest and another block near the minimum thickness.
4.5 The display element (CRT (cathode ray tube),(A-scan display, meter, or digital display) of the instrument must be adjusted
to present convenient values of thickness dependent on the range being used. The control for this function may have different
names on different instruments, including ran
...