ASTM F2174-02(2023)

Standard Practice for Verifying Acoustic Emission Sensor Response

SIGNIFICANCE AND USE
3.1 Degradation in sensor performance can occur due to dropping, mechanical shock while mounted on the test structure, temperature cycles, and so forth. It is necessary and desirable to have a simple measurement procedure that will check the consistency of sensor response, while holding all other variables constant.  
3.2 While test blocks of many different kinds have been used for this purpose for many years, an acrylic polymer rod offers the best all-around combination of suitable acoustic properties, practical convenience, ease of procurement, and low cost.  
3.3 Because the acoustic properties of the acrylic rod are known to depend on temperature, this practice requires that the rod, sensors, and couplant be stabilized at the same working temperature, prior to application of the practice.  
3.4 Attention should be paid to storage conditions for the acrylic polymer rod. For example, it should not be left in a freezing or hot environment overnight, unless it is given time for temperature stabilization before use.  
3.5 Properly applied and with proper record keeping, this practice can be used in many ways, such as:  
3.5.1 To determine when a sensor is no longer suitable for use.  
3.5.2 To check sensors that have been exposed to high-risk conditions such as dropping, overheating, and so forth.  
3.5.3 To get an early warning of sensor degradation over time.  
3.5.4 To obtain matched sets of sensors and preamplifiers.  
3.5.5 To verify sensors quickly but accurately in the field, and to assist troubleshooting when a channel does not pass a performance check.
SCOPE
1.1 This practice is used for routinely checking the sensitivity of acoustic emission (AE) sensors. It is intended to provide a reliable, precisely specified way of comparing a set of sensors or telling whether an individual sensor's sensitivity has degraded during its service life, or both.  
1.2 The procedure in this practice is not a “calibration” and does not give frequency-response information.  
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.4 This practice does not purport to recommend one sensor manufacturer over another nor does it imply that one type of sensor will react differently from another when using this procedure.  
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: 30-Apr-2023
• ICS: 17.140.01 - Acoustic measurements and noise abatement in general
• Technical Committee: F18 - Electrical Protective Equipment for Workers
• Drafting Committee: F18.55 - Inspection and Non-Destructive Test Methods for Aerial Devices

Relations

• Refers: ASTM E750-15(2020) - Standard Practice for Characterizing Acoustic Emission Instrumentation
• Effective Date: 01-Jun-2020
• Refers: ASTM E750-15 - Standard Practice for Characterizing Acoustic Emission Instrumentation
• Effective Date: 01-Dec-2015
• Refers: ASTM E976-10 - Standard Guide for Determining the Reproducibility of Acoustic Emission Sensor Response
• Effective Date: 01-Jun-2010
• Refers: ASTM E750-10 - Standard Practice for Characterizing Acoustic Emission Instrumentation
• Effective Date: 01-Jan-2010
• Refers: ASTM E976-05 - Standard Guide for Determining the Reproducibility of Acoustic Emission Sensor Response
• Effective Date: 01-Dec-2005
• Refers: ASTM E750-04 - Standard Practice for Characterizing Acoustic Emission Instrumentation
• Effective Date: 01-May-2004
• Refers: ASTM E976-00 - Standard Guide for Determining the Reproducibility of Acoustic Emission Sensor Response
• Effective Date: 10-Dec-2000
• Refers: ASTM E750-98 - Standard Practice for Characterizing Acoustic Emission Instrumentation
• Effective Date: 10-May-1998
• Refers: ASTM E650-97(2002)e1 - Standard Guide for Mounting Piezoelectric Acoustic Emission Sensors
• Effective Date: 10-Dec-1997
• Refers: ASTM E650-97(2007) - Standard Guide for Mounting Piezoelectric Acoustic Emission Sensors
• Effective Date: 10-Dec-1997

Overview

ASTM F2174-02(2023) - Standard Practice for Verifying Acoustic Emission Sensor Response is an international standard developed by ASTM to establish a reliable procedure for routinely checking the sensitivity and performance of acoustic emission (AE) sensors. Over time, AE sensors used in non-destructive testing and structural monitoring applications can experience degradation due to physical impacts, thermal cycles, and operational stress. This standard provides a consistent, practical method to detect such degradation, helping ensure the accuracy and reliability of measurement systems in critical environments.

Key Topics

• Routine Sensitivity Checks: This standard focuses on comparing sensor sensitivity among sets and detecting if an individual sensor’s performance has changed over its service life. It is designed as a check, not a calibration, and does not provide frequency response data.
• Use of Acrylic Rod Test Block: An acrylic polymer rod is recommended for its acoustic properties, convenience, and cost-effectiveness as the medium for sensor testing. The rod, sensors, and couplant must be temperature stabilized before use to ensure consistent results.
• Environmental Considerations: Proper storage and handling of the acrylic rod are emphasized, as its acoustic properties can vary with temperature. The rod should not be exposed to extreme cold or heat unless it is allowed to return to ambient working temperature prior to testing.
• Response Verification Method: The method involves mounting the sensor on the acrylic rod, applying a standardized pencil-lead break to generate a repeatable acoustic event, and recording the response. Results are compared across sensors to identify outliers and maintain system integrity.
• Criteria and Record Keeping: Sensors should not deviate more than ±2 dB from the group average. Sensors outside this range are flagged for repair or replacement. Consistent documentation and adherence to procedure improve the reliability of test results.

Applications

ASTM F2174-02(2023) is widely applicable in sectors utilizing acoustic emission testing, such as:

• Industrial Non-Destructive Testing (NDT): Enables regular performance verification for AE sensors used in monitoring pressure vessels, pipelines, and critical structures.
• Field Quality Assurance: Provides a quick and accurate approach for field technicians to verify sensor function and troubleshoot channels that fail performance checks.
• Asset Management: Early detection of degrading sensors supports predictive maintenance strategies, reduces downtime, and ensures compliance with safety standards.
• Sensor Inventory Management: Facilitates matching sets of sensors and preamplifiers, optimizing system configuration for consistent performance across equipment.

Related Standards

When implementing ASTM F2174-02(2023), the following standards may also be relevant:

• ASTM E650: Guide for Mounting Piezoelectric Acoustic Emission Sensors - details proper mounting techniques to ensure accurate sensor coupling.
• ASTM E750: Practice for Characterizing Acoustic Emission Instrumentation - provides guidelines for system evaluation and performance checking.
• ASTM E976: Guide for Determining the Reproducibility of Acoustic Emission Sensor Response - supports procedures to assess sensor response consistency.

Practical Value

By following this standard, organizations benefit from:

• Consistent Sensor Evaluation: Routine, repeatable checks help maintain sensor reliability and measurement accuracy.
• Reduced Risk of Undetected Degradation: Early warnings allow proactive replacement, minimizing faulty data collection.
• International Compatibility: Adherence to a globally recognized method supports compliance and confidence in cross-border operations.

Keywords: ASTM F2174-02, acoustic emission sensor response, sensitivity verification, acrylic rod, non-destructive testing, AE sensor performance check

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: F2174 − 02 (Reapproved 2023)
Standard Practice for
Verifying Acoustic Emission Sensor Response
This standard is issued under the fixed designation F2174; 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 E976 Guide for Determining the Reproducibility of Acoustic
Emission Sensor Response
1.1 This practice is used for routinely checking the sensi-
tivity of acoustic emission (AE) sensors. It is intended to
3. Significance and Use
provide a reliable, precisely specified way of comparing a set
3.1 Degradation in sensor performance can occur due to
of sensors or telling whether an individual sensor’s sensitivity
dropping, mechanical shock while mounted on the test
has degraded during its service life, or both.
structure, temperature cycles, and so forth. It is necessary and
1.2 The procedure in this practice is not a “calibration” and
desirable to have a simple measurement procedure that will
does not give frequency-response information.
check the consistency of sensor response, while holding all
other variables constant.
1.3 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
3.2 While test blocks of many different kinds have been
only.
used for this purpose for many years, an acrylic polymer rod
offers the best all-around combination of suitable acoustic
1.4 This practice does not purport to recommend one sensor
properties, practical convenience, ease of procurement, and
manufacturer over another nor does it imply that one type of
low cost.
sensor will react differently from another when using this
procedure.
3.3 Because the acoustic properties of the acrylic rod are
1.5 This standard does not purport to address all of the known to depend on temperature, this practice requires that the
safety concerns, if any, associated with its use. It is the rod, sensors, and couplant be stabilized at the same working
responsibility of the user of this standard to establish appro- temperature, prior to application of the practice.
priate safety, health, and environmental practices and deter-
3.4 Attention should be paid to storage conditions for the
mine the applicability of regulatory limitations prior to use.
acrylic polymer rod. For example, it should not be left in a
1.6 This international standard was developed in accor-
freezing or hot environment overnight, unless it is given time
dance with internationally recognized principles on standard-
for temperature stabilization before use.
ization established in the Decision on Principles for the
3.5 Properly applied and with proper record keeping, this
Development of International Standards, Guides and Recom-
practice can be used in many ways, such as:
mendations issued by the World Trade Organization Technical
3.5.1 To determine when a sensor is no longer suitable for
Barriers to Trade (TBT) Committee.
use.
2. Referenced Documents 3.5.2 To check sensors that have been exposed to high-risk
2 conditions such as dropping, overheating, and so forth.
2.1 ASTM Standards:
3.5.3 To get an early warning of sensor degradation over
E650 Guide for Mounting Piezoelectric Acoustic Emission
time.
Sensors
3.5.4 To obtain matched sets of sensors and preamplifiers.
E750 Practice for Characterizing Acoustic Emission Instru-
3.5.5 To verify sensors quickly but accurately in the field,
mentation
and to assist troubleshooting when a channel does not pass a
performance check.
This practice is under the jurisdiction of ASTM Committee F18 on Electrical
4. Apparatus
Protective Equipment for Workers and is the direct responsibility of Subcommittee
F18.55 on Inspection and Non-Destructive Test Methods for Aerial Devices.
4.1 Acrylic Polymer Cylindrical Rod (Fig. 1) should be
Current edition approved May 1, 2023. Published June 2023. Originally
used. The actual material of the acrylic polymer rod is
approved in 2002. Last previous edition approved in 2019 as F2174 – 02 (2019).
DOI: 10.1520/F2174-02R23.
poly(methyl methacrylate)(PMMA).
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4.1.1 Dimensions of the rod should be 78.74 cm (31 in.)
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
long by 3.81 cm (1.5 in.) in diameter with ends cut true and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. smooth with a surface finish of 0.4 μm rms (0.16 μin.).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2174 − 02 (2023)
FIG. 1 Acrylic Rod Description
4.1.2 Other lengths of rod are acceptable, provided that 5.5 Using the pencil lead source, break lead with the end of
there is sufficient distance to attenuate and prevent reflected the 9.3 mm lead in the center of the reference mark, within
signals from the non-sensor end of the rod reaching the sensor. 0.5 mm (0.020 in.) with a lead extension of 2.5 mm 6 0.5 mm
4.1.3 A permanent reference mark (for example, an “X”) is (0.1 in. 6 0.20 in.). A Nielsen shoe may be used to obtain a
placed on the rod at a distance of 10.16 cm (4 in.) from one consistent 30° angle between the lead and the surface. Hold the
end; this marks the spot where the lead is to be broken. It
...