1、 Reference number ISO 18175:2004(E) ISO 2004INTERNATIONAL STANDARD ISO 18175 First edition 2004-03-15 Non-destructive testing Evaluating performance characteristics of ultrasonic pulse-echo testing systems without the use of electronic measurement instruments Essais non destructifs valuation des car
2、actristiques fonctionnelles des systmes de contrle ultrasonore par rflexion sans utilisation dinstruments de mesure lectroniques ISO 18175:2004(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not
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7、w.iso.org Published in Switzerland ii ISO 2004 All rights reservedISO 18175:2004(E) ISO 2004 All rights reserved iiiContents Page Foreword iv 1 Scope 1 2 Normative references . 2 3 Terms and definitions. 2 4 Principle . 2 5 Significance and use 2 6 Procedures for obtaining ultrasonic response data .
8、 3 7 Report. 19 8 Precision and bias 20 9 Keywords . 20 Annex A (informative) Specific design for Figure 6 resolution reference block 21 ISO 18175:2004(E) iv ISO 2004 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards
9、bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizat
10、ions, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in th
11、e ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of
12、the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 18175 was prepared by Technical Committee ISO/TC 135, Non-destr
13、uctive testing, Subcommittee SC 3, Accoustical methods. INTERNATIONAL STANDARD ISO 18175:2004(E) ISO 2004 All rights reserved 1Non-destructive testing Evaluating performance characteristics of ultrasonic pulse-echo testing systems without the use of electronic measurement instruments WARNING This In
14、ternational 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 International Standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to us
15、e. 1 Scope This International Standard describes procedures for evaluating the following performance characteristics of ultrasonic pulse-echo examination instruments: horizontal limit and linearity; vertical limit and linearity; resolution-entry surface and far surface; sensitivity and noise; accura
16、cy of calibrated gain controls. Relevant terminology can be found in ASTM Terminology E 1316 and IEEE Standard 100. Evaluation of these characteristics is intended to be used for comparing instruments or, by periodic repetition, for detecting long- term changes in the characteristics of a given inst
17、rument that may be indicative of impending failure, and which, if beyond certain limits, will require corrective maintenance. Ultrasonic examination instruments using pulsed-wave trains and A-scan presentation (rf or video) may also be evaluated. The procedures are applicable to shop- or field-condi
18、tions and additional electronic measurement instrumentation is not required. This International Standard establishes no performance limits for examination systems; if such acceptance criteria are required, these must be specified by the using parties. Where acceptance criteria are implied herein the
19、y are only for the sake of example and are subject to more or less restrictive limits imposed by customers and end users controlling documents. The specific parameters to be evaluated, conditions and frequency of test, and report data required, must also be determined by the user. This International
20、 Standard may be used for the evaluation of a complete examination system, including transducer, instrument, interconnections, fixtures and connected alarm and auxiliary devices, primarily in cases where such a system is used repeatedly without change or substitution. This International Standard is
21、not intended to be used as a substitute for calibration of a system to inspect any given material. Required test apparatus includes selected reference blocks and a precision external attenuator (where specified) in addition to the instrument to be evaluated. Precautions relating to the applicability
22、 of the procedures and interpretation of the results are included. Alternate procedures, such as examples described in this International Standard, or others, may only be used with customer approval. ISO 18175:2004(E) 2 ISO 2004 All rights reserved2 Normative references The following referenced docu
23、ments are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 5577:2000, Non-destructive testing Ultrasonic Inspection Vocabulary ASTM E
24、 114-95, Standard Practice for Ultrasonic Pulse-Echo Straight-Beam Examination by the Contact Method ASTM E 127-98, Standard Practice for Fabricating and Checking Aluminum Alloy Ultrasonic Standard Reference Blocks ASTM E 214-01, Standard Practice for Immersed Ultrasonic Examination by the Reflectio
25、n Method Using Pulsed Longitudinal Waves ASTM E 428-00, Standard Practice for Fabrication and Control of Steel Reference Blocks Used in Ultrasonic Inspection ASTM E 1316-02a, Standard Terminology for Nondestructive Examinations JIS Z 2352, Method for assessing the overall performance characteristics
26、 of ultrasonic pulse echo testing instrument IEEE Std 100, IEEE Standard Dictionary of Electrical and Electronic Terms, Wiley-Interscience, New York 3 Terms and definitions For the purposes of this document the terms and definitions described in ISO 5577, ASTM E 1316 and IEEE Std 100 apply. 4 Princi
27、ple 4.1 An examination system to be evaluated comprises an ultrasonic pulse-echo instrument, transducer, interconnecting cables and couplant. For immersion examination systems suitable fixturing is required. 4.2 When checking an entire system to be used for a given inspection, test conditions are se
28、lected that are consistent with the intended end-use as determined by the user. 4.3 The ultrasonic response from appropriate reference blocks is obtained, and presented in numerical or graphical form. 5 Significance and use 5.1 This International Standard describes procedures applicable to both shop
29、- and field-conditions. More comprehensive or precise measurements of the characteristics of complete systems and their components will generally require laboratory techniques and electronic equipment such as oscilloscopes and signal generators. Substitution of these methods is not precluded where a
30、ppropriate; however, their usage is not within the scope of this International Standard. 5.2 This International Standard does not establish system acceptance limits, nor is it intended as a comprehensive equipment specification. ISO 18175:2004(E) ISO 2004 All rights reserved 35.3 While several impor
31、tant characteristics are included, others of possible significance in some applications are not covered. 5.4 Since the parameters to be evaluated and the applicable test conditions shall be specified, the practice described in this International Standard shall be prescribed only by those familiar wi
32、th ultrasonic NDT technology and the required tests shall be performed either by such a qualified person or under his/her supervision. 5.5 Implementation may require more detailed procedural instructions in the format of the using facility. 5.6 In the case of evaluation of a complete system, selecti
33、on of the specific tests to be made shall be made cautiously. If the related parameters are not critical in the intended application, then their inclusion may be unjustified, e.g., vertical linearity might be irrelevant for a go/no-go test with a flaw gate alarm, while horizontal linearity may be re
34、quired only for accurate flaw depth or thickness measurement from the instrument display. 5.7 No frequency of system evaluation or calibration is recommended or implied. This is the prerogative of the using parties and is dependent on application, environment and stability of equipment. 5.8 Certain
35、sections are applicable only to instruments having receiver gain controls calibrated in decibels (dB). While these may sometimes be designated “gain,” “attenuator” or “sensitivity” on various instruments, the term “gain controls” will be used in this International Standard when referring to those wh
36、ich specifically control instrument receiver gain but not including reject, electronic distance-amplitude compensation or automatic gain control. 5.9 These procedures can generally be applied to any combination of instrument and transducer of the commonly used types and frequencies, and to most stra
37、ight-beam examinations, either contact or immersed. Certain sections are also compatible with angle-beam, wheel, delay-line and dual probe techniques. Their use, however, shall be mutually agreed upon and so identified in the test report. 5.10 The validity of the results obtained will depend on the
38、precision of the instrument display readings. This is assumed to be 0,04 in ( 1 mm), yielding between 1 % and 2 % of full scale (fs) readability for available instrumentation having suitable screen graticules and display sharpness. 6 Procedures for obtaining ultrasonic response data 6.1 General 6.1.
39、1 A procedure, using this International Standard as a guide, shall be prepared for periodic checking of each specific type of instrument or system to be used. For each procedure determine, from the requesting documents, the instrument examination range to be evaluated, select the appropriate probe,
40、fixtures and reference blocks, and establish the required display conditions. Unless otherwise required, mid-range values are suggested for most panel controls and “reject” shall be off unless specifically desired to be evaluated. It may be desired to vary the instrument controls from these initial
41、values. If so, it is important to observe and report any anomalous effects on the parameters being evaluated when the controls are so varied. 6.1.2 When a procedure requires a change in receiver gain by the use of a calibrated control, it is assumed that those which increase sensitivity with higher
42、panel readings are designated “gain” and those which decrease sensitivity with higher readings are designated “attenuation.” Fine (reference) gain controls, when available, are usually not calibrated in decibels and increase sensitivity with clockwise rotation. 6.1.3 Although the procedures describe
43、d in this International Standard do not cover the use of electronic distance-amplitude compensation, its use is not precluded. If it is used to affect any one or combination of characteristics, measured under this document, then all characteristics should be evaluated with the same level of compensa
44、tion as was used on any one, and this level should be referenced in the report. If desired by the using parties, a dual set of test data may be made both with and without distance-amplitude compensation. ISO 18175:2004(E) 4 ISO 2004 All rights reserved6.1.4 If the display screen does not provide a s
45、uitable internal graticule, and deflection measurements are being made, fix the eye relative to the external scale in order to minimize parallax. This practice assumes reading precision of within 2 % of full scale. If, for any reason, this is not feasible for the instrument under test, estimate the
46、probable accuracy and include this in the report. Readability can sometimes be improved by the use of an external scale attached to the display screen face having 50 or 100 divisions for full scale. 6.1.5 When tests are being done by the contact method, position the probe securely and make certain t
47、hat couplant changes are not measurably affecting the results. See ASTM Practice E 114. 6.1.6 When using the immersion method, allow adequate time for thermal stabilization, remove bubbles and particles from the probe and test surfaces and maintain the probe manipulator and reference blocks in stabl
48、e positions. See ASTM Practice E 214. 6.2 Horizontal limit and linearity 6.2.1 Significance Horizontal limit and linearity have significance when determination of depth of a discontinuity is required. A specified minimum trace length is usually necessary to obtain the horizontal readability desired.
49、 Nonlinearity of sweep trace may affect accuracy of flaw depth or thickness determination made directly from the display screen. 6.2.2 Apparatus A reference block is required that will give several (preferably 11) noninterfering multiple back reflections for the sweep range and other test conditions of interest. Any block having good ultrasonic transmittivity, flat parallel faces, and a thickness of about one-tenth of the specified sweep range will usually be adequate. The aluminum blocks shown in Figure 1 will be satisfact
