ASTM E650-97

Designation: E 650 – 97 An American National Standard
Standard Guide for
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Mounting Piezoelectric Acoustic Emission Sensors
This standard is issued under the fixed designation E 650; 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 requires both appropriate sensor-mounting fixtures and consis-
tent sensor-mounting procedures.
1.1 This document provides guidelines for mounting piezo-
electric acoustic emission (AE) sensors.
5. Mounting Methods
1.2 This standard does not purport to address all of the
5.1 The purpose of the mounting method is to hold the
safety concerns, if any, associated with its use. It is the
sensor in a fixed position on a structure and to ensure that the
responsibility of the user of this standard to establish appro-
acoustic coupling between the sensor and the structure is both
priate safety and health practices and determine the applica-
adequate and constant. Mounting methods will generally fall
bility of regulatory limitations prior to use.
into one of the following categories:
2. Referenced Documents 5.1.1 Compression Mounts—The compression mount holds
the sensor in intimate contact with the surface of the structure
2.1 ASTM Standards:
through the use of force. This force is generally supplied by
E 976 Guide for Determining the Reproducibility of Acous-
2 springs, torqued-screw threads, magnets, tape, or elastic bands.
tic Emission Sensor Response
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The use of a couplant is strongly advised with a compression
E 1316 Terminology for Nondestructive Examinations
mount to maximize the transmission of acoustic energy
3. Terminology
through the sensor-structure interface.
5.1.2 Bonding—The sensor may be attached directly to the
3.1 Definitions of Terms Specific to This Standard:
structure with a suitable adhesive. In this method, the adhesive
3.1.1 bonding agent—a couplant that physically attaches
acts as the couplant. The adhesive must be compatible with the
the sensor to the structure.
structure, the sensor, the environment, and the test procedure.
3.1.2 couplant—a material used at the structure-to-sensor
interface to improve the transfer of acoustic energy across the
6. Mounting Requirements
interface.
6.1 Sensor Selection—The correct sensors should be chosen
3.1.3 mounting fixture—a device that holds the sensor in
to optimally accomplish the acoustic-emission test objective.
place on the structure to be monitored.
Sensor parameters to be considered are as follows: size,
3.1.4 sensor—a detection device that transforms the particle
sensitivity, frequency response, surface-motion response, and
motion produced by an elastic wave into an electrical signal.
environmental and material compatibility. When a multichan-
3.1.5 waveguide, acoustic—a device that couples acoustic
nel acoustic-emission test is being conducted, a subset of
energy from a structure to a remotely mounted sensor. For
sensors with characteristics similar to each other should be
example, a solid wire or rod, coupled to a sensor at one end and
selected. See Guide E 976 for methods of comparing sensor
to the structure at the other.
characteristics.
3.2 Definitions:
6.2 Structure Preparation—The contacting surfaces should
3.2.1 For definitions of additional terms relating to acoustic
be cleaned and mechanically prepared. This will enhance the
emission, refer to Terminology E 1316.
detection of the desired acoustic waves by assuring reliable
4. Significance and Use coupling of the acoustic energy from the structure to the sensor.
Preparation of these surfaces must be compatible with the
4.1 The methods and procedures used in mounting AE
construction materials used in both the sensor and the structure.
sensors can have significant effects upon the performance of
Possible losses in acoustic energy transmission caused by
those sensors. Optimum and reproducible detection of AE
coatings such as paint, encapsulants, loose-mill scale, weld
spatter, and oxides as well as losses due to surface curvature at
the contact area must be considered.
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This guide is under the jurisdiction of ASTM Committee E-7 on Nondestructive
6.3 Couplant or Bonding Agent Selection:
Testing and is the direct responsibility of Subcommittee E07.04 on Acoustic
Emission. 6.3.1 The type of couplant or bonding agent should be
Current edition approved Dec. 10, 1997. Published February 1998. Originally
selected with appropriate consideration for the effects of the
e1
published as E 650 – 85. Last previous edition E 650 – 85 (1992) .
environment (for example, temperature, pressure, composition
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Annual Book of ASTM Standards, Vol 03.03.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
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E 650
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