1、Designation: E2904 12E2904 17Standard Practice forCharacterization and Verification of Phased Array Probes1This standard is issued under the fixed designation E2904; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope Scope*1.1 This standard practice covers measurement procedures for evaluating certain characteristics of phased-array ultrason
3、icprobes that are used with phased-array ultrasonic examination instrumentation.1.2 This standard practice describes means for obtaining performance data that may be used to define the acoustic and electricresponses of phased-array ultrasonic probes including contact (with or without a wedge) and im
4、mersion linear phased-array probesused for ultrasonic nondestructive testing with central frequencies ranging from 0.5 MHz to 10 MHz. Frequencies outside of thisrange may use the same methods but the testing equipment may vary.1.3 When ultrasonic values dependent on material are specified in this do
5、cument, they are based on carbon steel with anultrasonic wave propagation speed of 5920 m/s (650 m/s) for longitudinal wave modes and 3255 m/s (630 m/s) for transverseor shear wave modes.1.4 This document describes some of the characterization and verification procedures that are to can be carried o
6、ut at the endstage of the manufacturing process of phased array probes. This document does not describe the methods or acceptance criteriaused to verify the performance of the entirecombined phased array ultrasonic instrument and probe.probe system.1.5 The values stated in SI units are to be regarde
7、d as the standard. The 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 responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenviro
8、nmental practices and determine theapplicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, G
9、uides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E1065 Practice for Evaluating Characteristics of Ultrasonic Search UnitsE1316 Terminology for Nondestructive Examinations3. Terminology3.1 Definition
10、s:3.1.1 For definitions of terms used in this practice, see Terminology E1316.3.1.2 Technical Specification of the Phased Array Probes:3.1.2.1 datasheetdefined as specification. This is the document that defines the general geometry and expected performanceof a specific model or part number.3.1.2.2
11、certificationdefined as measured performance of an individual probe. This is the document that reports the measuredperformance of a specific probe (specific to a serial number).3.1.2.3 probe typecontact or immersion.3.1.2.4 probe shape and sizeprobe form and dimensions.1 This practice/guide is under
12、 the jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.06 on UltrasonicMethod.Current edition approved Nov. 1, 2012Nov. 1, 2017. Published December 2012December 2017. Originally approved in 2012. Last previous edition approved in 2012 a
13、sE290412. DOI: 10.1520/E2904-12.10.1520/E2904-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This documen
14、t is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as app
15、ropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United St
16、ates13.1.3 Terminology for Array Probes:3.1.3.1 active aperturepitch times the number of elements.3.1.3.2 cross-couplingalso called “cross-talk.” An undesirable condition where array elements are activated, electrically oracoustically, by adjacent elements.3.1.3.2 element widthin a rectangular eleme
17、nt, the acoustic elements short dimension.3.1.3.3 element lengthin a rectangular element, the acoustic elements long dimension. See passive aperture (also calledelement elevation) and Fig. 2Fig. 3.3.1.3.4 element pitch (or pitch)the distance between the centers of two adjacent array elements.3.1.3.5
18、 passive aperturethe dimension of an array elements length.3.1.3.6 saw cutalso called “kerf,” space or gap. The space between adjacent elements.3.1.3.8 virtual probea group of individual array elements, pulsed simultaneously or at phasing intervals to generate a largeracoustic aperture.4. Summary of
19、 Practice4.1 The physical, acoustic and electrical characteristics which can be described from the data obtained by procedures outlinedin this guide are described as follows.FIG. 1 Schematic Showing Digitization RateE2904 1724.2 Physical AspectsIdentification and physical dimension aspects of the pr
20、obe should be noted. Details to be noted aredescribed in 7.1.4.3 Center Frequency, Bandwidth And Time ResponseSection 7.2 describes procedures for determining center frequency,bandwidth and time response of the individual elements of the linear array probe.4.4 Sensitivity Range Of ElementsSection 7.
21、3 describes a procedure to determine variation of sensitivity from one element tothe next based on a fixed input voltage.FIG. 2 Two-Channel Schematic Showing Measurement Technique for CrosstalkLegend:A = active aperture (number of active elements x element pitch)H = passive aperturee = element width
22、p = element pitchg = saw cut between elements (also called kerf or gap)FIG. 3 Schematic of Key Parameters for Linear ArraysE2904 1734.5 Probe SensitivityThe overall sensitivity performance of all the elements in the array is assessed in the procedure describedin 7.4.4.6 Element CrosstalkA procedure
23、for assessment of damping between elements to eliminate crosstalk is provided in 7.5.5. Significance and Use5.1 This standard practice is intended to provide standardized procedures for evaluating linear phased-array ultrasonic probes.It is not intended to define performance and acceptance criteria,
24、 but rather to provide data from which such criteria may beestablished.5.2 Implementation may require more detailed procedural instructions in a format of the using facility.5.3 The measurement data obtained may be employed by users of this guide to specify, describe, or provide performance criteria
25、for procurement and quality assurance, or service evaluation of the operating characteristics of linear phased-array ultrasonicprobes. All or portions of the standard practice may be used as determined by the user.5.4 The measurements are made primarily under pulse-echo conditions. To determine the
26、relative performance of a probeelement as either a transmitter or a receiver may require additional tests.5.5 While these procedures relate to many of the significant parameters, others that may be important in specific applicationsmay not be treated. These might include power handling capability, b
27、reakdown voltage, wear properties of contact units,radio-frequency interference, and the like.5.6 Care must be taken to ensure that comparable measurements are made and that users of the standard practice follow similarprocedures. The conditions specified or selected (if optional) may affect the tes
28、t results and lead to apparent differences.5.7 Interpretation of some test results, such as the shape of the frequency response curve, may be subjective. Small irregularitiesmay be significant. Interpretation of the test results is beyond the scope of this standard practice.5.8 Certain results obtai
29、ned using the procedures outlined may differ from measurements made with phased-array ultrasonic testinstruments. These differences may be attributed to differences in the nature of the experiment or the electrical characteristics ofthe instrumentation.5.9 The pulse generator used to obtain the freq
30、uency response and time response of the probe must have a rise time, duration,and spectral content sufficient to excite the probe over its full bandwidth, otherwise time distortion and erroneous results mayresult.5.10 While this standard practice is intended to provide standardized procedures for ev
31、aluating linear phased-array ultrasonicprobes, it may, with suitable modifications, be used for evaluation of configurations other than linear; e.g. 1.5D or 2D matrix arrayprobes.6. Instrumentation6.1 Electronic Instruments:6.1.1 The type of instrument(s) used for the tests specified in Section 7 sh
32、all be the same as that indicated on the Certificationreport and Table 2. They shall also be compliant with the applicable verification standard for the inspection unit.6.1.2 The following equipment is required in order to evaluate the probes in compliance with this standard:6.1.2.1 A pulser/receive
33、r with a minimum bandwidth of 20 MHz, digitizing to 100 MHz, or better, orand an oscilloscope (orequivalent) with a minimum bandwidth of 100 MHz. A phased-array instrument which contains the equivalent combination maybe used.6.1.2.2 Digitizing should be able to get 10 samples in maximum slope of wav
34、eform, as illustrated in Fig. 1.6.1.2.3 A frequency spectrum analyzer with a minimum bandwidth of 100 MHz or a digital oscilloscope/converter capable ofperforming fast Fourier transforms (FFT), and/or waveform capture and digital analysis.6.1.2.4 A phased array instrument may be used with a minimum
35、bandwidth of 20 MHz.6.1.2.4 An impedance analyzer.6.1.2.5 A waveform generator with burst-mode capability for a sine wave at the nominal frequency of the probe.6.1.3 The following additional equipment is optional:6.1.3.1 Ahydrophone with an active diameter two times smaller than the central ultrason
36、ic wavelength of the probe being tested,but no less than 0.5 mm.6.2 Test Blocks and Other Equipment:6.2.1 For Contact Arrays with Integral Wedges:6.2.1.1 Blocks made of the same material as the wedge (acrylic, polystyrene, etc.) in shapes complementary to the wedge,allowing sound paths to be equaliz
37、ed.6.2.2 For Contact Arrays (Replaceable Wedge or Direct Contact):6.2.2.1 Blocks with parallel surfaces made of the material specified in the datasheet.6.2.3 Immersion Testing for Immersion Arrays:E2904 1746.2.3.1 A large, flat reflective target. The lateral dimension of the target shall be large en
38、ough that spurious echoes do notinterfere with the return signal. The thickness of the block shall be equal to at least five times the wavelength of the probe beingtested, calculated based on the sound velocity in the target material.6.2.3.2 The water temperature in the immersion tank should be main
39、tained at room temperature during characterization of theimmersion probes in conjunction with the instrument(s).7. Procedures7.1 Physical Aspects:7.1.1 MethodPerform a visual inspection of the probe.7.1.1.1 Confirm that an identification marking is provided on the probe housing.7.1.1.2 Assess dimens
40、ional characteristics as required.7.1.1.3 Assess sealed edges as required.7.1.1.4 Assess electrical connections as required.7.1.1.5 Assess integral wedge surfaces as required.7.1.2 Acceptance CriteriaTolerance LimitsMake sure the probe is properly identified and assembled and that there are nosigns
41、of physical deterioration, which could reduce the reliability of the probe. For in-service applications, either comparecalibration results against the initial standard, or send probe back to manufacturer for re-certification.TABLE 1 List of Variables for Probe Manufacture and TestingInformation Need
42、ed Information Type(C, I, M)A Optional orRequired ObservationsName of Manufacturer I RequiredProbe type I RequiredInstruments and settings used in the test process I Required See Table 2Test conditions I Required Coupling medium, sound path, target, fixturingSee Table 2Probe Dimensions or shape M or
43、 I Optional Casing dimensionsElement shape and size (active and passiveapertures)I Optional Arrangement of the array(s)Dimensions and geometry of the array(s)Relative position of array in housing I Optional Location of first or last element in relation to thehousingPitch, gap between elements, eleme
44、nt width,length and dimensionsI Required Pitch, gap between elements (saw cut), andelement dimensions (length and width)Connector type I RequiredDimensions and material of integrated wedge I Optional Applicable to contact probesDimensions and geometry of integrated wedge(s)Wiring I Optional Cable le
45、ngth and external diameterCenter frequency, bandwidth, and time response M RequiredRelative Sensitivity Range of the Elements M or C in dB Required Basic voltage indication of each elementProbe sensitivity M RequiredElectrical Impedance M, I OptionalProbe crosstalk I or C in dB Optional Must state m
46、edium if crosstalk reportedA Legend:C = CalculationsI = InformationM = MeasurementTABLE 2 Instrumentation and Target RequirementsNOTE 1Table 2 gives a list of the instrumentation requirements toevaluate arrays.Instrument and Target Optional orRequired CommentsInstrument model RequiredInstrument cert
47、ification date RequiredInstrument serial number RequiredInstrument settings Required As needed to duplicatethe test. Example: pulsevoltage, pulse shape,pulse width, gainsettings, filters, receiverimpedanceTarget type/material RequiredTarget standardization date OptionalCoupling medium RequiredAverag
48、e sound path Required Distance or timeTest fixturing OptionalE2904 1757.2 Center Frequency, Bandwidth and Time Response (Waveform Duration)SeeAnnexA1,AnnexA2 andAnnexA4 inASTME1065 for guidelines.7.2.1 Measurements shall be taken on each element of the probe.7.2.2 For immersion probes, the target is
49、 placed at a water path as referenced in section 6.2, typically at the natural focus, ispositioned with a water path to the target in accordance to the manufacturers datasheet. Measurements shall be taken under normalincidence on any one of the detectable return echoes from the test block.7.2.3 For contact probes, the measurement shall be taken via direct contact (water or gel couplant) on the test block defined insection 6.2.7.2.4 The transmitter pulse should be a shock excitation having a duration of one-half cycle of the nominal probe frequency.7.
