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 Cast iron Yankee dryers can be up to 6.7 m [22 ft] in diameter, 7.3 m [24 ft] long, and weigh 91 000 Kg [100 tons], or more (refer to Fig. 1). Vessel thickness measurements are available from the paper/tissue machine operator. Cast iron is a brittle metal and has no specific yield point. Yankee dryers must maintain specific dimensional tolerances. When a pressurized Yankee or steam heated paper dryer (SHPD) remains stationary, it fills with condensate at a rapid rate. In an hour, a steam pressurized Yankee or SHPD can fill half way with condensate, doubling the weight on the frame, and the floor. Some Yankee owners have corporate requirements that a cast iron Yankee dryer remain stationary for 1/2 h, then rotation is required. Permission is required, if the Yankee is to remain stationary for more time. This issue should be discussed with the responsible person prior to the examination.FIG. 1 Yankee Dryer Drum5.2 Yankee dryers operate under a heated hood. The hood is in close proximity to the Yankee shell and allows only inches of clearance for the top half of the vessel.5.3 Cast iron steam heated paper machine dryers are 2 m [6 ft] in diameter, or more, and may be 9 m [30 ft] long.5.4 Grey cast iron experiences a continuing reduction in elastic modulus as it is stressed to increasing higher levels. It is prudent not to stress grey cast iron material beyond its operating stress level.5.5 Flaws to be found are the same as those in any cast and machined product. Attempts have been made to characterize strength properties of cast irons in compact tension tests. In a TAPPI sponsored laboratory study, two out of three cast iron compact tension specimens experienced unplanned failures. From that experience it was cautioned that cracks initiated and grew faster than expected resulting in brittle fracture before the process could be halted. The failure of these two coupons demonstrated the rate in which cracks can grow in these materials and the material’s inability to stop a crack once it begins to grow. In each case, crack advance was extremely rapid and without warning. (See Note 1.)NOTE 1: Alleveto, C., and Williams D., Acoustic Emission Evaluation of Yankee Dryer Shell Material, 1991 TAPPI Engineering Conference Proceedings, pages 475-480.5.6 Maximum Examination Pressure—Maximum Allowable Working Pressure for cast iron vessels is set based on ASME (Section VIII) pressure calculations based on thickness, radius, and material strength values, and will not exceed 10 bar [160 psi] and 230 °C [450 °F] (Specification A278/A278M). When vessels are pressurized, anomalies produce emission at pressures less than normal fill pressure. Historically, if there is damage in a cast iron pressure boundary, AE activity will begin at load/stress levels less than 50 % of operating. Defects as small as 3 mm [1/8 in.] have been found using AE, during steam pressurization to operating pressure.5.7 Pressure increments should not exceed 0.35 bar [5 psi] per minute. If pressurization medium is to be steam, the Yankee should have been through the warm-up process.5.8 Yankee dryers may receive a subsequent examination, if necessary, after the Yankee is rotated to remove any condensate present.5.9 Pressurization Schedule—Pressurization should proceed at rates that allow achieving maximum examination pressure within a 30 minute period. During pressurization, pressure holds are not necessary; however, they may be useful for reasons other than measurement of AE. Pressure hold upon achieving maximum examination pressure may be up to 30 min.5.10 Excess background noise may distort AE data or render the AE measurements useless. Users must be aware of the following common sources of background noise: (measurable flow noise); mechanical contact with the vessel by objects; electromagnetic interference (EMI) from cranes, and radio frequency interference (RFI) from nearby broadcasting facilities and from other sources; leaks at pipe or hose connections, or rain drops. This practice should not be used if background noise cannot be eliminated or controlled.5.11 Other Non-destructive test methods may be used to evaluate the significance of AE sources. Magnetic particle, ultrasonic, and radiographic examinations have been used to establish circumferential position, depth, and dimensions of flaws that produce AE. Procedures for using other NDT nethods are beyond the scope of this practice.1.1 This practice is no longer being updated but is being retained for historical value due to the procedures herein that are unique to the AE community.1.2 This practice provides guidelines for carrying out acoustic emission (AE) examinations of Yankee and Steam Heated Paper Dryers (SHPD) of the type to make tissue, paper, and paperboard products.1.3 This practice requires pressurization to levels used during normal operation. The pressurization medium may be high temperature steam, air, or gas. The dryer is also subjected to significant stresses during the heating up and cooling down periods of operation. Acoustic Emission data maybe collected during these time periods but this testing is beyond the scope of this document.1.4 The AE measurements are used to detect, as well as, localize emission sources. Other methods of nondestructive testing (NDT) may be used to further evaluate the significance of acoustic emission sources.1.5 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.1.6 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 This guide can be used in the development of acoustic emission applications for structural health monitoring.5.2 Accuracy, robustness, and efficiency of AE-SHM can be enhanced by following the steps and fundamental principles described in the guide.1.1 Structural Health Monitoring (SHM) is a field of engineering that deals with diagnosis and monitoring of structures during their operation. The primary goal of SHM is detection, identification, assessment, and monitoring of flaws or fault conditions that affect or may affect the future safety or performance of structures. SHM combines elements of nondestructive testing and evaluation, condition/process monitoring, statistical pattern recognition, and physical modeling.1.2 The acoustic emission (AE) method uniquely fits the concept of SHM due to its capabilities to periodically or continuously examine structures and assess structural integrity during their normal operation.1.3 In this guide, the definitions and fundamental principles for applying the AE method for SHM tasks are elaborated. This includes:1.3.1 Terminology and definitions of SHM by the AE method,1.3.2 Outline the recommended process of AE-SHM, and1.3.3 Fundamental requirements regarding development of the SHM procedures, including selection of appropriate AE apparatus, data acquisition and analysis methods, diagnosis, monitoring and prediction.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 High pressure fluids being pumped in all oil field applications often stress iron pipes where subsequent failure can lead to injury to personnel or equipment. These forgings are typically constructed from 4700 series low carbon steel with a wall thickness in excess of 1.25 cm [0.5 in.], dependent on the manufacturers' specification. The standard method to certify that these iron segments can withstand operational pressures is to perform dye penetrant (PT) or magnetic particle penetrant (MT) tests, or both, to reveal defects (cracks and corrosion). As these methods are subject to interpretation by the human eye, it is desirable to employ a technique whereby a sensor based system can provide a signal to either pass or fail the test object. To that end, the acoustic emission (AE) method provides the requisite data from which acceptance/rejection can be made by a computer, taking the human out of the loop, providing that a human has correctly programmed the acceptance criteria. Most of these pipe segments are not linear, thus a 3D defect location method is desirable. The 3D source indication represents the spatial location of the defect without regard to its orientation, recognizing the source location is only approximate due to sound propagation through the part and water bath.5.2 The immersed 3D approach is found to be preferable due to the large number of parts to be examined. The 3D system is easily replicated and standardized in that all sensor locations are fixed to the exterior of the fluid bath. Multiple parts may be easily placed into an assembly, allowing all to be examined in a single test, thus accelerating throughput. Attaching a minimum of eight AE sensors to the tank enhances the probability that a sufficient number of AE hits in an event will occur, allowing for an approximate location determination. When an indication of a defect is observed, the subject part is identified by the spatial location allowing it to be removed for further examination, or rejected for service. An immersed test configuration is shown in Fig. 1a and b.FIG. 1 (a) Immersion Bath With Permanently Attached AE Sensors on Exterior (Circles)FIG. 1 (b) Photo of Part Under Test (continued)5.3 The non-immersed examination is equally effective in detecting defects, but requires more time to assemble in that sensors must be attached to the part for each examination. Moreover, the fluid fill and air purge times are much longer than in the immersed bath immersion. The non-immersed test layout and photo are shown in Fig. 2a and b. Note the sensors are indicated with the symbol x.FIG. 2 (a) Is the Layout, With sensors 1–4, of A Typical Non-immersed Test as is Shown in the Photo (b)FIG. 2 (b) Sensors 1–4, of A Typical Non-immersed Test (continued)1.1 This practice is no longer being updated but is being retained for historical value as it represents the only AE practice using hydrostatic testing in which the sensors are not in direct contact with the part.1.2 In the preferred embodiment, this practice examines immersed low carbon, forged piping being immersed in a water tank with the acoustic sensors permanently mounted on the tank walls rather than temporarily on the part itself. The pipes are monitored while being internally loaded (stressed) by hydrostatic means up to 1000 bar.1.3 This practice examines either an immersed pipe, or non-immersed pipe being stressed by internal hydrostatic means to create acoustic emissions when cracks are present. However, the non-immersed method is time consuming, requiring placement and removal of sensors for each pipe inspected, while the immersed method has sensors permanently mounted, providing consistent sensor coupling to the tank-eliminating reinstallation. The non-immersed method is not recommended for the specified reasons and only the immersed method will be discussed throughout the remainder of the practice. This is similar to pressure vessel testing described in Practice E569, but uses hydrostatic means not included in that standard.1.4 This Acoustic Emission (AE) method addresses examination for monitoring low carbon, forged piping systems being internally loaded (stressed) by hydrostatic means up to 1000 bar [15,000 psi] while being immersed in a water bath to facilitate sensor coupling.1.5 The basic functions of an AE monitoring system are to detect, locate, and classify emission sources. Other methods of nondestructive testing (NDT) may be used to further evaluate the significance of acoustic emission sources.1.6 This practice can be used to replace visual methods, which are unreliable and have significant safety risks.1.7 This practice describes procedures to install and monitor acoustic emission resulting from local anomalies stimulated by controlled hydrostatic pressure.1.8 Other methods of nondestructive testing (NDT) may be used to further evaluate the significance of acoustic emission sources.1.9 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.1.10 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.1.11 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 permits testing of the major components of a digger derrick generated by the rapid release of energy from localized sources within the digger derrick under controlled loading. The energy releases occur during intentional application of a predetermined load. These energy releases can be monitored and interpreted by qualified individuals. Acceptance/rejection criteria are beyond the scope of this test method. The test may be discontinued at any time to investigate a particular area of concern, or to prevent a fault from continuing to ultimate failure of the digger derrick resulting from the application of the test load.5.2 This test method provides a means of detecting acoustic emission sources that may be defects, irregularities, or both, affecting the structural integrity or intended use of the aerial personnel device.5.3 Significant sources of acoustic emission found with this test method shall be evaluated by either more refined acoustic emission test techniques or by other nondestructive methods (visual, liquid penetrant, radiography, ultrasonic, magnetic particle, etc.). Other nondestructive methods may be required in order to precisely locate defects in the digger derrick, and to estimate their size. Additional tests are outside the scope of this test method.5.4 Defective areas found in digger derricks by this test method should be repaired and retested as appropriate. Repair procedure recommendations are outside the scope of this test method. Repair procedure recommendations are outside the scope of this test method.1.1 This test method covers a procedure for acoustic emission (AE) testing of digger derricks.1.1.1 Equipment Covered—This test method applies to special multipurpose vehicle-mounted machines, commonly known as digger derricks. These machines are primarily designed to dig holes, set poles, and position materials and apparatus.1.1.1.1 Insulated and non-insulated type digger derricks may be evaluated with this test method.1.1.1.2 Digger derricks, if so equipped to position personnel or equipment, or both, may also be evaluated with this test method in conjunction with Test Method F914.1.1.2 Equipment Not Covered—Excluded from this test method are general-purpose cranes designed only for lifting service and machines primarily designed only for digging holes.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, ultrasonic, magnetic particle, liquid penetrant, and visual inspection.1.3 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.FIG. 1  Digger Derrick Nomenclature1.4 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 This practice does not rely on absolute quantities of AE parameters. It relies on trends of cumulative AE counts that are measured during a specified sequence of loading cycles. This practice includes an example of examination settings and acceptance criteria as a nonmandatory appendix.FIG. 1 Recommended Features of the Apparatus4.2 Acoustic emission (AE) counts were used as a measure of AE activity during development of this practice. Cumulative hit duration may be used instead of cumulative counts if a correlation between the two is determined. Several processes can occur within the structure under examination. Some may indicate unacceptable flaws (for example, growing resin cracks, fiber fracture, delamination). Others may produce AE but have no structural significance (for example, rubbing at interfaces). The methodology described in this practice prevents contamination of structurally significant data with emission from insignificant sources.4.3 Background Noise—Background noise can distort interpretations of AE data and can preclude completion of an examination. Examination personnel should be aware of sources of background noise at the time examinations are conducted. AE examinations should not be conducted until such noise is substantially eliminated.4.4 Mechanical Background Noise—Mechanical background noise is generally induced by structural contact with the container under examination. Examples are: personnel contact, wind borne sand or rain. Also, leaks at pipe connections may produce background noise.4.5 Electronic Noise—Electronic noise such as electromagnetic interference (EMI) and radio frequency interference (RFI) can be caused by electric motors, overhead cranes, electrical storms, welders, etc.4.6 Airborne Background Noise—Airborne background noise can be produced by gas leaks in nearby equipment.4.7 Accuracy of the results from this practice can be influenced by factors related to setup and calibration of instrumentation, background noise, material properties, and structural characteristics.1.1 This practice covers guidelines for acoustic emission (AE) examinations of pressurized containers made of fiberglass reinforced plastic (FRP) with balsa cores. Containers of this type are commonly used on tank trailers for the transport of hazardous chemicals.1.2 This practice is limited to cylindrical shape containers, 0.5 m [20 in.] to 3 m [120 in.] in diameter, of sandwich construction with balsa wood core and over 30 % glass (by weight) FRP skins. Reinforcing material may be mat, roving, cloth, unidirectional layers, or a combination thereof. There is no restriction with regard to fabrication technique or method of design.1.3 This practice is limited to containers that are designed for less than 0.520 MPa [75.4 psi] (gage) above static pressure head due to contents.1.4 This practice does not specify a time interval between examinations for re-qualification of a pressure container.1.5 This practice is used to determine if a container is suitable for service or if follow-up NDT is needed before that determination can be made.1.6 Containers that operate with a vacuum are not within the scope of this practice.1.7 Repair procedures are not within the scope of this practice.1.8 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.1.9 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 8.1.10 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 Controlled stimulation, that is, the application of mechanical or thermal load, can generate AE from flawed areas of the structure. Sources may include flaw growth, oxide fracture, crack face stiction and release on load application, and crack face rubbing.5.2 The load range above normal service (peak) load is used to propagate fatigue cracks in the plastically strained region ahead of the crack tip. Crack propagation may not be a reliable source of AE, depending on the alloy and microstructure, the amount (rate) of crack extension, and possibility of brittle fracture in a segment of crack extension.5.3 Load increases resulting in significant ductile tearing may produce less emission than expected for the amount of crack growth. Processes that result in more brittle cleavage fractures are more detectable and produce more emission for smaller amounts of flaw growth. These include corrosion fatigue and stress corrosion cracking modes of flaw growth, and would also be more likely in cast or welded structures than in fabricated (forged, rolled, or extruded) structures. Distributed defect structures such as hydrogen embrittlement, or creep cavitation in high temperature steels, may also produce significant emission without evidence of an existing crack-like flaw.5.4 Application and relaxation of load can produce secondary mechanically-induced emission that is not related to flaw extension. This includes crack face stiction release on loading—usually evidenced by emission at the same rising load value regardless of peak load; or crack face rubbing on load release as the fracture surfaces come back together.5.5 The load rate can be a significant concern as instrumentation can become saturated with AE activity. The ability to differentiate real data from background noise can be compromised.5.6 Background noise must be fully investigated and minimized before any AE monitoring can begin.AbstractThis practice provides guidelines for acoustic emission (AE) examination or monitoring of structures, such as pressure vessels, piping systems, or other structures that can be stressed by mechanical or thermal means. The basic functions of an AE monitoring system are to detect, locate, and classify emission sources. Other methods of nondestructive testing (NDT) may be used to further evaluate the significance of acoustic emission sources. Acoustic emission examination of a structure usually requires application of a mechanical or thermal stimulus. Such stimulation produces changes in the stresses in the structure. During stimulation of a structure, AE from discontinuities (such as cracks and inclusions) and from other areas of stress concentration, or from other acoustic sources (such as leaks, loose parts, and structural motion) can be detected by an instrumentation system, using sensors which, when stimulated by stress waves, generate electrical signals. Annual calibration and verification of pressure transducer, AE sensors, preamplifiers, signal processor, and AE electronic waveform generator should be performed.1.1 This practice provides guidelines for acoustic emission (AE) monitoring of structures, such as pressure vessels, piping systems, or other structures that can be stressed by mechanical or thermal means.1.2 The basic functions of an AE monitoring system are to detect, locate, and classify emission sources. Other methods of nondestructive testing (NDT) may be used to further evaluate the significance of reported acoustic emission sources.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 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 This test method provides a means for a reliable field determination of fuel dilution that is quick and preparation-free. Results are obtained in approximately 1 min. Such a method is used, for example, at remote railroad depots where it is impractical to carry out a standard laboratory method for determination of fuel dilution, such as described in Test Method D7593, but it is a critical need to determine if fuel has contaminated the lubricant. If fuel has contaminated the lubricant, this is significantly detrimental to the machinery and it is typically serviced immediately. Further, the fuel can ignite at the high temperatures encountered in machinery lubricant paths.1.1 This test method describes a means for determining the amount of fuel dilution present in an in-service lubricant. This is achieved by drawing into a surface acoustic wave (SAW) sensor vapor from the lubricant. Fuel vapor will be absorbed by the SAW sensor’s polymer coating. The amount of absorbance is then related to fuel content in the lubricant.1.2 The range of fuel dilution capable of being measured by the test method is from 0.1 % to 10.0 % by mass fuel dilution.1.3 This test method is specifically tailored to determining the fuel dilution of in-service lubricants, including newly utilized lubricants. The method is applicable to contamination with diesel, gasoline, and jet fuels.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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. See Section 9.1.6 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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4.1 Acoustic Emission data acquisition can be affected by numerous factors associated with the electronic instrumentation, cables, sensors, sensor holders, couplant, the examination article on which the sensor is mounted, background noise, and the user's settings of the acquisition parameters (for example, threshold).4.2 This guide is not intended to replace annual (or semi-annual) instrumentation calibration (see Practice E750) or sensor recertification (see Practice E1781).4.3 This guide is not intended to replace routine electronic evaluation of AE instrumentation or routine reproducibility verification of AE sensors (see Guide E976).4.4 This guide is not intended to verify the maximum processing capacity or speed of an AE system.4.5 This guide 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 guide to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.1.1 System performance verification methods launch stress waves into the examination article on which the sensor is mounted. The resulting stress wave travels in the examination article and is detected by the sensor(s) in a manner similar to acoustic emission.1.2 This guide describes methods which can be used to verify the response of an Acoustic Emission system including sensors, couplant, sensor mounting devices, cables and system electronic components.1.3 Acoustic emission system performance characteristics, which may be evaluated using this document, include some waveform parameters, and source location accuracy.1.4 Performance verification is usually conducted prior to beginning the examination.1.5 Performance verification can be conducted during the examination if there is any suspicion that the system performance may have changed.1.6 Performance verification may be conducted after the examination has been completed.1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.8 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.1.9 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 Sodars have found wide applications for the remote measurement of wind and turbulence profiles in the atmosphere, particularly in the gap between meteorological towers and the lower range gates of wind profiling radars. The sodar’s far field acoustic power is also used for refractive index calculations and to estimate atmospheric stability, heat flux, and mixed layer depth (1-5).3 Sodars are useful for these purposes because of strong interaction between sound waves and the atmosphere’s thermal and velocity micro-structure that produce acoustic returns with substantial signal-to-noise ratios (SNR). The returned echoes are Doppler-shifted in frequency. This frequency shift, proportional to the radial velocity of the scattering surface, provides the basis for wind measurement. Advantages offered by sodar wind sounding technology include reasonably low procurement, operating, and maintenance costs, no emissions of eye-damaging light beams or electromagnetic radiation requiring frequency clearances, and adjustable frequencies and pulse lengths that can be used to optimize data quality at desired ranges and range resolutions. When properly sited and used with adequate sampling methods, sodars can provide continuous wind and turbulence profile information at height ranges from a few tens of meters to over a kilometer for typical averaging periods of 1 to 60 minutes.1.1 This guide describes the application of acoustic remote sensing for measuring atmospheric wind and turbulence profiles. It includes a summary of the fundamentals of atmospheric sound detection and ranging (sodar), a description of the methodology and equipment used for sodar applications, factors to consider during site selection and equipment installation, and recommended procedures for acquiring valid and relevant data.1.2 This guide applies principally to pulsed monostatic sodar techniques as applied to wind and turbulence measurement in the open atmosphere, although many of the definitions and principles are also applicable to bistatic configurations. This guide is not directly applicable to radio-acoustic sounding systems (RASS), or tomographic methods.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this guide.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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