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ASTM E664-93(2000)

(Practice)

Standard Practice for the Measurement of the Apparent Attenuation of Longitudinal Ultrasonic Waves by Immersion Method

Standard Practice for the Measurement of the Apparent Attenuation of Longitudinal Ultrasonic Waves by Immersion Method

SCOPE
1.1 This practice describes a procedure for measuring the apparent attenuation of ultrasound in materials or components with flat, parallel surfaces using conventional pulse-echo ultrasonic flaw detection equipment in which reflected indications are displayed in an A-scan presentation.  
1.2 The measurement procedure is readily adaptable for the determination of relative attenuation between materials. For absolute (true) attenuation measurements, indicative of the intrinsic nature of the material, it is necessary to correct for specimen geometry, sound beam divergence, instrumentation, and procedural effects. These results can be obtained with more specialized ultrasonic equipment and techniques.  
1.3 The values stated in inch-pound units are to be regarded as the standard.
1.4 This standard does not purport to address all of the safety problems, 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
09-May-2000
ICS
17.140.01 - Acoustic measurements and noise abatement in general
Technical Committee
E07 - Nondestructive Testing
Drafting Committee
E07.06 - Ultrasonic Method
Current Stage
Ref Project

Relations

Replaced By
ASTM E664-93(2005) - Standard Practice for the Measurement of the Apparent Attenuation of Longitudinal Ultrasonic Waves by Immersion Method
Effective Date
01-Jan-2005
Referred By
ASTM E543-21 - Standard Specification for Agencies Performing Nondestructive Testing
Effective Date
10-May-2000

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ASTM E664-93(2000) - Standard Practice for the Measurement of the Apparent Attenuation of Longitudinal Ultrasonic Waves by Immersion MethodASTM E664-93(2000) - Standard Practice for the Measurement of the Apparent Attenuation of Longitudinal Ultrasonic Waves by Immersion Method
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ASTM E664-93(2000) - Standard Practice for the Measurement of the Apparent Attenuation of Longitudinal Ultrasonic Waves by Immersion Method
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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: E 664 – 93 (Reapproved 2000)
Standard Practice for the
Measurement of the Apparent Attenuation of Longitudinal
Ultrasonic Waves by Immersion Method
This standard is issued under the fixed designation E 664; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2 Definitions of Terms Specific to This Standard:
3.2.1 apparent attenuation—the observed ultrasound en-
1.1 This practice describes a procedure for measuring the
ergy loss. In addition to the true loss, the apparent attenuation
apparent attenuation of ultrasound in materials or components
may also include losses attributable to instrumentation, speci-
with flat, parallel surfaces using conventional pulse-echo
men configuration, beam divergence, interface reflections, and
ultrasonic flaw detection equipment in which reflected indica-
measurement procedure.
tions are displayed in an A-scan presentation.
3.2.2 attenuation—a factor that describes the decrease in
1.2 The measurement procedure is readily adaptable for the
ultrasound intensity with distance. Normally expressed in
determination of relative attenuation between materials. For
decibels per unit length.
absolute (true) attenuation measurements, indicative of the
intrinsic nature of the material, it is necessary to correct for
NOTE 1—The attenuation parameter is sometimes expressed in nepers
specimen geometry, sound beam divergence, instrumentation, (Np) per unit length. The value in decibels (dB) is 8.68 times the value in
nepers. If the loss over a path is 1 Np, then the amplitude has fallen to 1/e
andproceduraleffects.Theseresultscanbeobtainedwithmore
of its initial value (e = 2.7183. . .).
specialized ultrasonic equipment and techniques.
1.3 The values stated in inch-pound units are to be regarded
3.2.3 decibel (dB)—twenty times the logarithmic expres-
as the standard.
sion of the ratio of two amplitudes.
1.4 This standard does not purport to address all of the
dB 5 20 log ~amplitude ratio!
safety concerns, if any, associated with its use. It is the
3.2.4 true attenuation—that portion of the observed ultra-
responsibility of the user of this standard to establish appro-
sound energy loss which is intrinsic to the medium through
priate safety and health practices and determine the applica-
which the ultrasound propagates. True attenuation losses may
bility of regulatory limitations prior to use.
be attributed to the basic mechanisms of absorption and
2. Referenced Documents scattering.
2.1 ASTM Standards:
4. Summary of Practice
E 214 Practice for Immersed Ultrasonic Examination by the
2 4.1 This practice describes a procedure for determining
Reflection Method Using Pulsed Longitudinal Waves
apparent attenuation by measuring the decay of multiple back
E 317 Practice for Evaluating Performance Characteristics
reflections of longitudinal ultrasonic waves introduced into
of Ultrasonic Pulse-Echo Testing Systems Without the Use
specimens with flat, parallel surfaces by the immersion tech-
of Electronic Measurement Instruments
2 nique.
E 1316 Terminology for Nondestructive Examinations
5. Significance and Use
3. Terminology
5.1 The measurement of apparent attenuation in materials is
3.1 Definitions:
useful in applications such as the comparison of heat treat-
3.1.1 For definitions of terms used in this practice, see
ments of different lots of material or the assessment of the
Terminology E 1316.
degradation of materials due to environment.
5.2 Several different modes of wave vibration can be
propagated in solids. This practice is concerned with the
This practice is under the jurisdiction of ASTM Committee E-7 on Nonde-
structive Testing, and is the direct responsibility of Subcommittee E 07.06 on
attenuation associated with longitudinal waves introduced into
Ultrasonic Method.
the specimen by the immersion method.
Current edition approved Sept. 15, 1993. Published November 1993. Originally
e1
5.3 This practice allows for the comparison of the apparent
published as E 664 – 78. Last previous edition E 664 – 78 (1989) .
Annual Book of ASTM Standards, Vol 03.03. attenuations of geometrically similar specimens.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E 664 – 93 (2000)
parallelism, surface finish, etc. However, useful apparent attenuation
5.4 For the determination of apparent attenuation, the pro-
information can be obtained if the requirements of 7.1 and 7.2 are
cedures described herein are valid only for measurements in
satisfied.
the far field of the ultrasonic beam.
8. Procedure
6. Apparatus
8.1 Measure the thickness of the specimen to an accuracy of
6.1 Ultrasonic Flaw Detection System— A system capable
60.001 in. (60.03 mm) or 60.1 %, whichever is greater.
of generating, receiving, and displaying electrical pulses at the
8.2 Place the sample in a suitable immersion tank.
frequency of interest. Display shall be an A-scan presentation.
6.1.1 Performance Characteristics—The vertical linearity 8.3 Place the search unit in a fixture suitable for manipulat-
limits shall be determined as specified in Practice E 317. All
ing the sound entry angle and lateral position. Position the
measurements shall be made only within the linear ranges of search unit over the sample, and angulate the beam to obtain
t
...

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1.1 This practice covers a general procedure for using the Impulse Excitation Method (IEM) to facilitate natural frequency measurement and detection of defects and material variations in metallic and non-metallic parts. This test method is also known as Impulse Excitation Technique (IET), Acoustic Resonance Testing (ART), ping testing, tap testing, and other names. IEM is listed as a Resonance Ultrasound Spectroscopy (RUS) method. The method applies an impulse load to excite and then record resonance frequencies of a part. These recorded resonance frequencies are compared to a reference population or within subgroups/families of examples of the same part, or modeled frequencies, or both.  
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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.
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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).  
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5.1 This practice is intended to provide standardized procedures for evaluating ultrasonic search units. It is not intended to define performance and acceptance criteria, but rather to provide data from which such criteria may be established.  
5.2 These procedures are intended to evaluate the characteristics of single-element piezoelectric search units.  
5.3 Implementation may require more detailed procedural instructions in a format of the using facility.  
5.4 The measurement data obtained may be employed by users of this practice to specify, describe, or provide a performance criteria for procurement and quality assurance, or service evaluation of the operating characteristics of ultrasonic search units. All or portions of the practice may be used as determined by the user.  
5.5 The measurements are made primarily under pulse-echo conditions. To determine the relative performance of a search unit as either a transmitter or a receiver may require additional tests.  
5.6 While these procedures relate to many of the significant parameters, others that may be important in specific applications may not be treated. These might include power handling capability, breakdown voltage, wear properties of contact units, radio-frequency interference, and the like.  
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5.8 Interpretation of some test results, such as the shape of the frequency response curve, may be subjective. Small irregularities may be significant. Interpretation of the test results is beyond the scope of this practice.  
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5.3 Source location accuracy is influenced by factors that affect elastic wave propagation, by sensor coupling, and by signal processor settings.  
5.4 It is possible to measure AE and identify AE source locations of indications that cannot be detected by other NDT methods, due to factors related to methodological, material, or structural characteristics.  
5.5 In addition to immediate evaluation of the AE sources, a permanent record of the total data collected (AE plus pressure system parameters measured) provides an archival record which can be re-evaluated.
SCOPE
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4.1 The methods and procedures used in mounting AE sensors can have significant effects upon the performance of those sensors. Optimum and reproducible detection of AE requires both appropriate sensor-mounting fixtures and consistent sensor-mounting procedures.
SCOPE
1.1 This document provides guidelines for mounting piezoelectric acoustic emission (AE) sensors.  
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 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.  
1.3 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 and health 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.

  • Guide
    4 pages
    English language
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  • Guide
    4 pages
    English language
    sale 15% off