4.1 Transfer Standards—One purpose of this test method is for the direct calibration of displacement transducers for use as secondary standards for the calibration of AE sensors for use in nondestructive evaluation. For this purpose, the transfer standard should be high fidelity and very well behaved and understood. If this can be established, the stated accuracy should apply over the full frequency range up to 1 MHz.NOTE 1: The stated accuracy applies only if the transfer standard returns to quiescence, following the transient input, before any wave reflected from the boundary of the calibration block returns to the transfer standard (∼100 μs). For low frequencies with periods on the order of the time window, this condition is problematical to prove.4.2 Applications Sensors—This test method may also be used for the calibration of AE sensors for use in nondestructive evaluation. Some of these sensors are less well behaved than devices suitable for a transfer standard. The stated accuracy for such devices applies in the range of 100 kHz to 1 MHz and with less accuracy below 100 kHz.1.1 This test method covers the requirements for the absolute calibration of acoustic emission (AE) sensors. The calibration yields the frequency response of a transducer to waves, at a surface, of the type normally encountered in acoustic emission work. The transducer voltage response is determined at discrete frequency intervals of approximately 10 kHz up to 1 MHz. The input is a given well-established dynamic displacement normal to the mounting surface. The units of the calibration are output voltage per unit mechanical input (displacement, velocity, or acceleration).1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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, health, and environmental 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.

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5.1 Acoustic emission examination of a structure requires application of a mechanical or thermal stimulus. In this case, the system operating conditions provide the stimulation. During operation of the pressurized system, AE from active discontinuities such as cracks or from other acoustic sources such as leakage of high-pressure, high-temperature fluids can be detected by an instrumentation system using sensors mounted on the structure. The sensors are acoustically coupled to the surface of the structure by means of a couplant material or pressure on the interface between the sensing device and the structure. This facilitates the transmission of acoustic energy to the sensor. When the sensors are excited by acoustic emission energy, they transform the mechanical excitations into electrical signals. The signals from a detected AE source are electronically conditioned and processed to produce information relative to source location and other parameters needed for AE source characterization and evaluation.5.2 AE monitoring on a continuous basis is a currently available method for continuous surveillance of a structure to assess its continued integrity. The use of AE monitoring in this context is to identify the existence and location of AE sources. Also, information is provided to facilitate estimating the significance of the detected AE source relative to continued pressure system operation.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.1.1 This practice provides guidelines for continuous monitoring of acoustic emission (AE) from metal pressure boundaries in industrial systems during operation. Examples are pressure vessels, piping, and other system components which serve to contain system pressure. Pressure boundaries other than metal, such as composites, are specifically not covered by this document.1.2 The functions of AE monitoring are to detect, locate, and characterize AE sources to provide data to evaluate their significance relative to pressure boundary integrity. These sources are those activated during system operation, that is, no special stimulus is applied to produce AE. Other methods of nondestructive testing (NDT) may be used, when the pressure boundary is accessible, to further evaluate or substantiate the significance of detected AE sources.1.3 Units—The values stated in either SI units or inch-pound units are to be regarded 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 standards.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. For specific precautionary statements, see Section 6.1.5 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.

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5.1 Because of safety considerations, regulatory agencies (for example, U.S. Department of Transportation) require periodic tests of pressurized vessels used in commercial aviation. (see Section 49, Code of Federal Regulations). AE testing has become accepted as an alternative to the common hydrostatic proof test.5.2 An AE test should not be conducted for a period of one year after a common hydrostatic test. See Note 1.NOTE 1: The Kaiser effect relates to the irreversibility of acoustic emission which results in decreased emission during a second pressurization. Common hydrostatic tests use a relatively high test pressure (200 % of normal service pressure). (See Section 49, Code of Federal Regulations.) If an AE test is performed too soon after such a hydrostatic pressurization, the AE results will be insensitive below the previous maximum test pressure.5.3 Acoustic Emission is produced when an increasing stress level in a material causes crack growth in the material or stress related effects in a corroded surface (for example, crack growth in or between metal crystallites or spalling and cracking of oxides and other corrosion products).5.4 While background noise may distort AE data or render it useless, heating the vessels inside an industrial oven is an almost noise free method of pressurization. Further, source location algorithms using over-determined data sets will often allow valid tests in the presence of otherwise interfering noise sources. Background noise should be reduced or controlled but the sudden occurrence of such noise does not necessarily invalidate a test.1.1 This practice is commonly used for periodic inspection and testing of welded steel gaseous spheres (bottles) is the acoustic emission (AE) method. AE is used in place of hydrostatic volumetric expansion testing. The periodic inspection and testing of bottles by AE testing is achieved without depressurization or contamination as is required for hydrostatic volumetric expansion testing.1.2 The required test pressurization is achieved by heating the bottle in an industrial oven designed for this purpose. The maximum temperature needed to achieve the AE test pressure is ≤250°F (121°C).1.3 AE monitoring of the bottle is performed with multiple sensors during the thermal pressurization.1.4 This practice was developed for periodic inspection and testing of pressure vessels containing Halon (UN 1044), which is commonly used aboard commercial aircraft for fire suppression. In commercial aircraft, these bottles are hermetically sealed by welding in the fill port. Exit ports are opened by explosively activated burst disks. The usage of these pressure vessels in transportation is regulated under US Department of Transportation (DOT), Code of Federal Regulations CFR 49. A DOT special permit authorizes the use of AE testing for periodic inspection and testing in place of volumetric expansion and visual inspection. These bottles are spherical with diameters ranging from 5 to 16 in. (127 to 406 mm).1.5 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.6 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. Specific precautionary statements are given in Section 8.1.7 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.

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4.1 Detection and location of AE sources in weldments during fabrication may provide information related to the integrity of the weld. Such information may be used to direct repair procedures on the weld or as a guide for application of other nondestructive evaluation (NDE) methods. A major attribute of applying AE for in-process monitoring of welds is the ability of the method to provide immediate real-time information on weld integrity. This feature makes the method useful to lower weld costs by repairing defects at the most convenient point in the production process. The AE activity from discontinuities in the weldment is stimulated by the thermal stresses from the welding process. The AE activity resulting from this stimulation is detected by AE sensors in the vicinity of the weldment, which convert the acoustic waves into electronic signals. The AE instrumentation processes signals and provides means for immediate display or indication of AE activity and for permanent recordings of the data.4.2 Items to be considered in preparation and planning for monitoring should include but not be limited to the following:4.2.1 Description of the system or object to be monitored or examined,4.2.2 Extent of monitoring, that is, entire weld, cover passes only, and so forth,4.2.3 Limitations or restrictions on the sensor mounting procedures, if applicable,4.2.4 Performance parameters to be established and maintained during the AE system verification procedure (sensitivity, location accuracy, and so forth),4.2.5 Maximum time interval between AE system verification checks,4.2.6 Performance criteria for purchased equipment,4.2.7 Requirements for permanent records of the AE response, if applicable,4.2.8 Content and format of test report, if required, and4.2.9 Operator qualification and certification, if required.1.1 This practice provides recommendations for acoustic emission (AE) monitoring of weldments during and immediately following their fabrication by continuous welding processes.1.2 The procedure described in this practice is applicable to the detection and location of AE sources in weldments and in their heat-affected zone during fabrication, particularly in those cases where the time duration of welding is such that fusion and solidification take place while welding is still in progress.1.3 The effectiveness of acoustic emission to detect discontinuities in the weldment and the heat-affected zone is dependent on the design of the AE system, the AE system verification procedure, the weld process, and the material type. Materials that have been monitored include low-carbon steels, low-alloy steels, stainless steels, and some aluminum alloys. The system performance must be verified for each application by demonstrating that the defects of concern can be detected with the desired reliability.1.4 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.1.5 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.

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5.1 This practice provides information necessary to document the accuracy and performance of an Acoustic Emission system. This information is useful for reference purposes to assure that the instrumentation performance remains consistent with time and use, and provides the information needed to adjust the system to maintain its consistency.5.2 The methods set forth in this practice are not intended to be either exclusive or exhaustive.5.3 Difficult or questionable instrumentation measurements should be referred to electronics engineering personnel.5.4 It is recommended that personnel responsible for carrying out instrument measurements using this practice should be experienced in instrumentation measurements, as well as all the required test equipment being used to make the measurements.AbstractThis practice deals with the testing and measurement of operating characteristics of acoustic emission (AE) electronic components or units. This practice is not intended for routine checks of acoustic emission instrumentation, but rather for periodic evaluation or in the event of a malfunction. The sensor is not addressed in this document other than suggesting methods for standardizing system gains (equalizing them channel to channel) when sensors are present. The test methods and measurement techniques used and their corresponding results should be recorded in documentation, which consists of photographs, charts or graphs, calculations, and tabulations where applicable. This practice does not cover the testing of the computer or computer peripherals used in conjunction with AE systems that use them to control the collection, storage, display, and analysis of data. Instead a manufacturer's specification should be provided for such purpose.1.1 This practice is recommended for use in testing and measuring operating characteristics of acoustic emission electronic components or units. (See Appendix X1 for a description of components and units.) It is not intended that this practice be used for routine checks of acoustic emission instrumentation, but rather for periodic evaluation or in the event of a malfunction. The sensor is not addressed in this document other than suggesting methods for standardizing system gains (equalizing them channel to channel) when sensors are present.1.2 Where the manufacturer provides testing and measuring details in an operating and maintenance manual, the manufacturer's methods should be used in conjunction with the methods described in this practice.1.3 The methods (techniques) used for testing and measuring the components or units of acoustic emission instrumentation, and the results of such testing and measuring should be documented. Documentation should consist of photographs, screenshots, charts or graphs, calculations, and tabulations where applicable.1.4 AE systems that use computers to control the collection, storage, display, and data analysis, might include waveform collection as well as a wide selection of measurement parameters (features) relating to the AE signal. The manufacturer provides a specification for each system that specifies the operating range and conditions for the system. All calibration and acceptance testing of computer-based AE systems must use the manufacturer's specification as a guide. This practice does not cover testing of the computer or computer peripherals.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.6 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.1.7 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.

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5.1 The AE produced during the production of a spot-weld can be related to weld quality parameters such as the strength and size of the nugget, the amount of expulsion, and the amount of cracking. Therefore, in-process AE monitoring can be used both as an examination method, and as a means for providing feedback control.1.1 This practice describes procedures for the measurement, processing, and interpretation of the acoustic emission (AE) response associated with selected stages of the resistance spot-welding process.1.2 This practice also provides recommendations for feedback control by utilizing the measured AE response signals during the spot-welding process.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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 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.

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5.1 This test method provides a means of evaluating acoustic emissions generated by the rapid release of energy from localized sources within an aerial personnel device under controlled loading. The resultant energy releases occur during intentional application of a controlled predetermined load. These energy releases can be monitored and interpreted by qualified individuals.5.2 This test method permits testing of the major components of an aerial personnel device under controlled loading. This test method utilizes objective criteria for evaluation and may be discontinued at any time to investigate a particular area of concern or prevent a fault from continuing to ultimate failure.5.3 This test method provides a means of detecting acoustic emission sources that may be defects or irregularities, or both, affecting the structural integrity or intended use of the aerial personnel device.5.4 Sources of acoustic emission found with this test method shall be evaluated by either more refined acoustic emission test methods or other nondestructive techniques (visual, liquid penetrant, radiography, ultrasonics, magnetic particle, etc.). Other nondestructive tests may be required to locate defects present in aerial personnel devices.5.5 Defective areas found in aerial personnel devices by this test method should be repaired and retested as appropriate. Repair procedure recommendations are outside the scope of this test method.1.1 This test method describes a procedure for non-destructive testing using acoustic emission (AE) testing for aerial personnel devices, which do not have a supplemental load handling attachment.1.1.1 Equipment Covered—This test method covers the following types of vehicle-mounted insulated aerial personnel devices:1.1.1.1 Extensible boom aerial personnel devices,1.1.1.2 Articulating boom aerial personnel devices, and1.1.1.3 Any combination of 1.1.1.1 and 1.1.1.2.1.1.2 Equipment Not Covered—This test method does not cover any of the following equipment:1.1.2.1 Material-handling aerial devices,1.1.2.2 Digger-derricks with platform, and1.1.2.3 Cranes with platform.1.2 The AE test method is used to detect and area-locate emission sources. Verification of emission sources may require the use of other nondestructive test (NDT) methods, such as radiography, ultrasonics, magnetic particle, liquid penetrant, and visual inspection. Warning—This test method requires that external loads be applied to the superstructure of the vehicle under test. During the test, caution must be taken to safeguard personnel and equipment against unexpected failure or instability of the vehicle or components.NOTE 1: This test method is not intended to be a stand alone NDT method for the verification of the structural integrity of an aerial device. Other NDT methods should be used to supplement the results.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 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.

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5.1 The AE examination method detects damage in RTRP. The damage mechanisms detected in RTRP are as follows: resin cracking, fiber debonding, fiber pullout, fiber breakage, delamination, and bond or thread failure in assembled joints. Flaws in unstressed areas and flaws which are structurally insignificant will not generate AE.5.2 This practice is convenient for on-line use under operating conditions to determine structural integrity of in-service RTRP usually with minimal process disruption.5.3 Flaws located with AE should be examined by other techniques; for example, visual, ultrasound, and dye penetrant, and may be repaired and retested as appropriate. Repair procedure recommendations are outside the scope of this practice.1.1 This practice covers acoustic emission (AE) examination or monitoring of reinforced thermosetting resin pipe (RTRP) to determine structural integrity. It is applicable to lined or unlined pipe, fittings, joints, and piping systems.1.2 This practice is applicable to pipe that is fabricated with fiberglass and carbon fiber reinforcements with reinforcing contents greater than 15 % by weight. The suitability of these procedures must be demonstrated before they are used for piping that is constructed with other reinforcing materials.1.3 This practice is applicable to tests below pressures of 35 MPa absolute [5000 psia].1.4 This practice is limited to pipe up to and including 0.6 m [24 in.] in diameter. Larger diameter pipe can be examined with AE, however, the procedure is outside the scope of this practice.1.5 This practice applies to examinations of new or in-service RTRP.1.6 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.1.7 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 to determine the applicability of regulatory limitations prior to use. For more specific safety precautionary information, see 8.1.1.8 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.

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5.1 Because of safety considerations, regulatory agencies (for example, U.S. Department of Transportation) require periodic examinations of vessels used in transportation of industrial gases (see Section 49, Code of Federal Regulations). The AE examination has become accepted as an alternative to the common hydrostatic proof test. In the common hydrostatic test, volumetric expansion of vessels is measured.5.2 An AE examination should not be performed for a period of one year after a common hydrostatic test. See Note 2.NOTE 2: The Kaiser effect relates to decreased emission that is expected during a second pressurization. Common hydrostatic tests use a relatively high pressure (167 % of normal service pressure). (See Section 49, Code of Federal Regulations.) If an AE examination is performed too soon after such a pressurization, the AE results will be insensitive to a lower examination pressure (that is, the lower pressure that is associated with an AE examination).5.3 Pressurization: 5.3.1 General practice in the gas industry is to use low pressurization rates. This practice promotes safety and reduces equipment investment. The AE examinations should be performed with pressurization rates that allow vessel deformation to be in equilibrium with the applied load. Typical current practice is to use rates that approximate 3.45 MPa/h [500 psi/h].5.3.2 Gas compressors heat the pressurizing medium. After pressurization, vessel pressure may decay as gas temperature equilibrates with ambient conditions.5.3.3 Emission from flaws is caused by flaw growth and secondary sources (for example, crack surface contact and contained mill scale). Secondary sources can produce emission throughout vessel pressurization.5.3.4 When pressure within a vessel is low, and gas is the pressurizing medium, flow velocities are relatively high. Flowing gas (turbulence) and impact by entrained particles can produce measurable emission. Considering this, acquisition of AE data may commence at some pressure greater than starting pressure (for example, 1/3 of maximum examination pressure).5.3.5 Maximum Test Pressure—Serious flaws usually produce more acoustic emission (that is, more events, events with higher peak amplitude) from secondary sources than from flaw growth. When vessels are pressurized, flaws produce emission at pressures less than normal fill pressure. A maximum examination pressure that is 10 % greater than normal fill pressure allows measurement of emission from secondary sources in flaws and from flaw growth.5.3.6 Pressurization Schedule—Pressurization should proceed at rates that do not produce noise from the pressurizing medium and that allow vessel deformation to be in equilibrium with applied load. Pressure holds are not necessary; however, they may be useful for reasons other than measurement of AE.5.4 Excess background noise may distort AE data or render them useless. Users must be aware of the following common sources of background noise: high gas-fill rate (measurable flow noise); mechanical contact with the vessel by objects; electromagnetic interference (EMI) and radio frequency interference (RFI) from nearby broadcasting facilities and from other sources; leaks at pipe or hose connections; and airborne sand particles, insects, or rain drops. This practice should not be used if background noise cannot be eliminated or controlled.5.5 Alternate procedures are found in ISO 16148 and CGA C18. These include hydrostatic proof pressurization of individual vessels and data interpretation using modal analysis techniques1.1 This practice provides guidelines for acoustic emission (AE) examinations of seamless pressure vessels (tubes) of the type used for distribution or storage of industrial gases.1.2 This practice requires pressurization to a level greater than normal use. Pressurization medium may be gas or liquid.1.3 This practice does not apply to vessels in cryogenic service.1.4 The AE measurements are used to detect and locate emission sources. Other nondestructive test (NDT) methods must be used to evaluate the significance of AE sources. Procedures for other NDT techniques are beyond the scope of this practice. See Note 1.NOTE 1: Shear wave, angle beam ultrasonic examination is commonly used to establish circumferential position and dimensions of flaws that produce AE. Time of Flight Diffraction (TOFD), ultrasonic examination is also commonly used for flaw sizing.1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.6 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. Specific precautionary statements are given in Section 7.1.7 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.

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4.1 General—Ultrasonic testing is a widely used nondestructive method for the examination of a material. The majority of ultrasonic examinations are performed using transducers that directly convert electrical energy into acoustic energy through the use of piezoelectric crystals. This guide describes an alternate technique in which electromagnetic energy is used to produce acoustic energy inside an electrically conductive or ferromagnetic material. EMATs have unique characteristics when compared to conventional piezoelectric ultrasonic search units, making them a significant tool for some ultrasonic examination applications.4.2 Principle—An electromagnetic acoustic transducer (EMAT) generates and receives ultrasonic waves without the need to contact the material in which the acoustic waves are traveling. The use of an EMAT requires that the material to be examined be electrically conductive or ferromagnetic, or both. There are two basic components of an EMAT system, a magnet and a coil. The magnet may be an electromagnet or a permanent magnet, which is used to produce a magnetic field in the material under test. The coil is driven using alternating current at the desired ultrasonic frequency. The coil and AC current also induce a surface magnetic field in the material under test. In the presence of the static magnetic field, the surface current experiences Lorentz forces that produce the desired ultrasonic waves. Upon reception of an ultrasonic wave, the surface of the conductor oscillates in the presence of a magnetic field, thus inducing a voltage in the coil. The transduction process occurs within an electromagnetic skin depth. The EMAT forms the basis for a very reproducible noncontact system for generating and detecting ultrasonic waves.4.3 Specific Advantages—Since an EMAT technique does not have to be in contact with the material under examination, no fluid couplant is required. Important consequences of this include applications to moving objects, in remote or hazardous locations, to objects at elevated temperatures, or to objects with rough surfaces. The EMAT technique is environmentally safe since it does not use potentially polluting or hazardous chemicals. The technique facilitates the rapid scanning of components having complex geometries. EMAT signals are highly reproducible as a consequence of the manner in which the acoustic waves are generated. EMATs can also produce horizontally polarized shear (SH) waves without mode conversion and can accommodate scanning while using SH waves. (Note that in order to produce this wave mode by conventional ultrasonic techniques, either an epoxy or a highly viscous couplant is required. Thus, conventional ultrasonic techniques do not lend themselves easily to scanning when using SH wave modes.) Additionally, EMATs can allow the user to electronically steer shear waves.4.4 Specific Limitations—EMATs have very low efficiency as compared with conventional ultrasonic methods, with insertion losses of 40 dB or more. The EMAT technique can be used only on materials that are electrical conductors or are ferromagnetic. Highly corroded surfaces, especially inner surfaces, may render EMAT unsuitable for use if the surface disturbs the generation of the Lorentz forces. The design of EMAT probes is usually more complex than comparable piezoelectric search units, and are usually relatively large in size. Due to their low efficiency, EMATs usually require more specialized instrumentation for the generation and detection of ultrasonic signals. High transmitting currents, low-noise receivers, and careful electrical matching are imperative in system design. In general, EMAT probes are application-specific, in the same way as are piezoelectric transducers.1.1 This guide is intended primarily for tutorial purposes. It provides an overview of the general principles governing the operation and use of electromagnetic acoustic transducers (EMATs) for ultrasonic examination.1.2 This guide describes a non-contact technique for coupling ultrasonic energy into an electrically conductive or ferromagnetic material, or both, through the use of electromagnetic fields. This guide describes the theory of operation and basic design considerations as well as the advantages and limitations of the technique.1.3 This guide is intended to serve as a general reference to assist in determining the usefulness of EMATs for a given application as well as provide fundamental information regarding their design and operation. This guide provides guidance for the generation of longitudinal, shear, Rayleigh, and Lamb wave modes using EMATs.1.4 This guide does not contain detailed procedures for the use of EMATs in any specific applications; nor does it promote the use of EMATs without thorough testing prior to their use for examination purposes. Some applications in which EMATs have been applied successfully are outlined in Section 9.1.5 Units—The values stated in inch-pound units are to be regarded as the standard. The SI values given in parentheses are for information only.1.6 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.1.7 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.

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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.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).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 are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.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, health, and environmental 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.

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5.1 APR technology is used for detection, location and identification of internal diameter (ID) flaws-indications and blockages in tube bundles.5.2 Reliable and accurate examination of tube bundles is of great importance in different industries. On-time detection of flaws reduces a risk of catastrophic failure and minimizes unplanned shutdowns of plant equipment. Fast examination capability is of great importance due to reduction of maintenance time.5.3 APR examinations are performed for quality control of newly manufactured tube bundles as well as for in-service inspection.5.4 Performing an APR examination requires access to an open end of each tube to be examined.5.5 Flaws that can be readily detected and identified include but are not limited to through-wall holes, ID pitting, erosion, blockages, bulging due to creep and plastic deformation due to bending.5.6 APR can be applied to tube bundles made of metal, graphite, plastic or other solid materials with straight and curved sections. The APR technology has been found effective on tubes with diameters between 12.7 mm [1/2 in.] to 101.6 mm [4 in.] and lengths up to 18 metres [60 feet].5.7 Closed cracks on ID surface, without significant geometrical alternation on ID surface, may not be detected by APR.5.8 APR technology can be used for flaw sizing when special signal and data analysis methods are developed and applied.5.9 In addition to detection of flaws and blockages, APR technology can be applied for assessing tube ID surface cleanliness, providing valuable information for equipment maintenance and improving its performance.5.10 Other nondestructive test methods may be used to verify and evaluate the significance of APR indications, their exact position, depth, dimension and orientation. These include remote visual inspection, eddy current and ultrasonic testing.5.11 Procedures for using other NDT methods are beyond the scope of this practice.5.12 Acceptable flaw size can be calculated using methods of fracture mechanics, numerical modeling, or both. These calculations are beyond the scope of this document.1.1 This practice describes use of Acoustic Pulse Reflectometry (APR) technology for examination of the internal surface of typical tube bundles found in heat exchangers, boilers, tubular air heaters and reactors, during shutdown periods.1.2 The purpose of APR examination is to detect, locate and identify flaws such as through-wall holes, ID wall loss due to pitting and/or erosion as well as full or partial tube blockages. APR may not be effective in detecting cracks with tight boundaries.1.3 APR technology utilizes generation of sound waves through the air in the examined tube, then detecting reflections created by discontinuities and/or blockages. Analysis of the initial phase (positive or negative) and the shape of the reflected acoustic wave are used to identify the type of flaw causing the reflection.1.4 When proper methods of signal and data analysis are developed, APR technology can be applied for sizing of flaw/blockage indications.1.5 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 standards.1.6 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.1.7 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.

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5.1 Paper machine rolls can range in size from 2.4 to 9 m [8 to 30 ft] long, with a shell thickness of from 12.5 to 75 mm [0.5 to 3 in.,] and 300 to 1200 mm [12 to 48 in.] diameter. Depending on purpose, paper machine rolls can weigh as little as 60 000 kg [13 000 lb] to as much as 27 500 kg [60 000 lb].5.2 If indications are found during this procedure it can be repeated, with additional sensors to refine source location accuracy.5.3 Removal of rolls for traditional NDT examination may be impractical and may not be sensitive enough to locate small defects.5.4 Traditional AE examination, whereby the roll is subjected to load greater than service load to detect crack extension, risks damage to the roll and is best employed as a follow-up NDT examination.5.5 Manual rotation through a full revolution subjects existing cracks to tensile and compressive forces which can open and close existing cracks, and cause friction at the crack surfaces.5.6 Excess background noise (overhead cranes, nearby maintenance activities) may distort AE data or render it useless. Users must be aware of the following common sources of background noise: bearing noise (lack of lubrication, spalling, and so forth), mechanical contact with the roll by other objects, electromagnetic interference (EMI) and radio frequency interference (RFI) from nearby broadcasting facilities and from other sources. This practice should not be used if background noise cannot be eliminated or controlled.5.7 Other Non-destructive test methods may be used to evaluate the significance of AE indications. Traditional AE has been used to confirm the existence of the AE indication and fine tune the location. Magnetic particle, ultrasonic and radiographic examinations have been used to establish the position, depth and dimensions of the indication. Procedures for using other NDT methods are beyond the scope of this practice.1.1 This practice provides guidelines for acoustic emission (AE) examinations of non-pressure, paper machine rolls.1.2 This practice utilizes a slow rotation of the roll to produce a full load cycle where load is provided by the weight of the roll suspended from its bearings or other journal support mechanism(s).1.3 This practice is used for detection of cracks and other discontinuities in rolls that produce frictional acoustic emission during rotation.1.4 The AE measurements are used to detect or locate emission sources, or both. Other nondestructive test (NDT) methods must be used to evaluate the significance of AE sources. Procedures for other NDT techniques are beyond the scope of this practice. See Note 1.NOTE 1: Traditional AE examination, magnetic particle examination, shear wave ultrasonic examination, and radiography are commonly used to establish the exact position and dimensions of flaws that produce AE.1.5 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.1.6 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. Specific precautionary statements are given in Section 8.1.7 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.

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5.1 This test method provides a means of evaluating acoustic emissions generated by the rapid release of energy from localized sources within an APD under controlled loading. The resultant energy releases occur during intentional application of a controlled predetermined load. These energy releases can be monitored and interpreted by qualified individuals.5.2 This test method permits testing of the major components of an aerial device under controlled loading. This test method utilizes objective criteria for evaluation and may be discontinued at any time to investigate a particular area of concern or prevent a fault from continuing to ultimate failure.5.3 This test method provides a means of detecting acoustic emissions that may be defects or irregularities, or both, affecting the structural integrity or intended use of the aerial device.5.4 Sources of acoustic emission found with this test method shall be evaluated by either more refined acoustic emission test methods or other nondestructive techniques (visual, liquid penetrant, radiography, ultrasonics, magnetic particle, etc.). Other nondestructive tests may be required to locate defects present in APDs.5.5 Defective areas found in aerial devices by this test method should be repaired and retested as appropriate. Repair procedure recommendations are outside the scope of this test method.1.1 This test method describes a procedure for acoustic emission (AE) testing of aerial personnel devices (APDs) with supplemental load handling attachments.1.1.1 Equipment Covered—This test method covers the following types of vehicle-mounted aerial personnel devices with supplemental load handling attachments:1.1.1.1 Extensible-boom APDs,1.1.1.2 Articulating-boom APDs, and1.1.1.3 Any combination of 1.1.1.1 and 1.1.1.2.1.1.2 Equipment Not Covered—This test method does not cover any of the following equipment:1.1.2.1 Aerial personnel devices without supplemental load handling attachments,1.1.2.2 Digger-derricks with platform,1.1.2.3 Cranes with platform, and1.1.2.4 Aerial devices with load-lifting capabilities located anywhere other than adjacent to the platform.NOTE 1: This test method is not intended to be a stand-alone NDT method for the verification of the structural integrity of an aerial device. Other NDT methods should be used to supplement the results.1.2 The AE test method is used to detect and area-locate emission sources. Verification of emission sources may require the use of other nondestructive test (NDT) methods, such as radiography, ultrasonics, magnetic particle, liquid penetrant, and visual inspection. (Warning—This test method requires that external loads be applied to the superstructure of the vehicle under test. During the test, caution must be taken to safeguard personnel and equipment against unexpected failure or instability of the vehicle or components.)1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 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.

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4.1 Leakage of gas or liquid from a pressurized system, whether through a crack, orifice, seal break, or other opening, may involve turbulent or cavitational flow, which generates acoustic energy in both the external atmosphere and the system pressure boundary. Acoustic energy transmitted through the pressure boundary can be detected at a distance by using a suitable acoustic emission sensor.4.2 With proper selection of frequency passband, sensitivity to leak signals can be maximized by eliminating background noise. At low frequencies, generally below 100 kHz, it is possible for a leak to excite mechanical resonances within the structure that may enhance the acoustic signals used to detect leakage.4.3 This practice is not intended to provide a quantitative measure of leak rates.1.1 This practice describes a passive method for detecting and locating the steady state source of gas and liquid leaking out of a pressurized system. The method employs surface-mounted acoustic emission sensors (for non-contact sensors see Test Method E1002), or sensors attached to the system via acoustic waveguides (for additional information, see Terminology E1316), and may be used for continuous in-service monitoring and hydrotest monitoring of piping and pressure vessel systems. High sensitivities may be achieved, although the values obtainable depend on sensor spacing, background noise level, system pressure, and type of leak.1.2 Units—The values stated in either SI units or inch-pound units are to be regarded 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 standards.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.

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