1、BSI Standards PublicationBS EN ISO 16826:2014Non-destructive testing Ultrasonic testing Examination for discontinuitiesperpendicular to the surface(ISO 16826:2012)BS EN ISO 16826:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO16826:2014. It is identical
2、 to ISO 16826:2012. It supersedes BS EN583-4:2002 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee WEE/46, Non-destructive testing.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not
3、purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 82682 5ICS 19.100Compliance with a British Standard cannot confer immunity fromlegal obligation
4、s.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 March 2014.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 16826 March 2014 ICS 19.100 Supersedes EN 583-4:2002English Version N
5、on-destructive testing - Ultrasonic testing - Examination for discontinuities perpendicular to the surface (ISO 16826:2012) Essais non destructifs - Contrle par ultrasons - Contrle des discontinuits perpendiculaires la surface (ISO 16826:2012) Zerstrungsfreie Prfung - Ultraschallprfung - Prfung auf
6、Inhomogenitten senkrecht zur Oberflche (ISO 16826:2012) This European Standard was approved by CEN on 9 February 2014. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without
7、any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other lang
8、uage made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmar
9、k, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE F
10、OR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 16826:2014 EBS EN ISO 16826:
11、2014EN ISO 16826:2014 (E) 3 Foreword The text of ISO 16826:2012 has been prepared by Technical Committee ISO/TC 135 “Non-destructive testing” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 16826:2014 by Technical Committee CEN/TC 138 “Non-destructive te
12、sting” the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2014, and conflicting national standards shall be withdrawn at the latest by September 2
13、014. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 583-4:2002. According to the CEN-CENELEC Internal Reg
14、ulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland,
15、Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 16826:2012 has been approved by CEN as EN ISO 16826:2014 without any modification. BS EN ISO
16、16826:2014ISO 16826:2012(E) ISO 2012 All rights reserved iiiContents Page Introduction v 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Tandem examination.1 4.1 General .1 4.2 Time base adjustment.2 4.3 Setting of sensitivity .3 4.4 Determination of examination zones.3 4.5 DGS-diagram
17、 for tandem examination4 4.6 Corrections of sensitivity .5 4.7 Object with concentric surfaces 5 5 LLT-examination7 5.1 General .7 5.2 Time base adjustment and determination of discontinuity depth .8 5.3 Setting of sensitivity .9 5.4 Determination of examination depth.9 5.5 DGS-diagrams for LLT-exam
18、ination11 5.6 Correction of sensitivity .11 Annex A (informative) Nomograms for determination of tandem distances for convex (Figure A.1) and concave (Figure A.2) scanning surface .12 Foreword iv BS EN ISO 16826:2014ISO 16826:2012(E) iv ISO 2012 All rights reservedForeword ISO (the International Org
19、anization for Standardization) is a worldwide federation of national standards 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 establi
20、shed has the right to be represented on that committee. International organizations, 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 standardizatio
21、n. International Standards are drafted in accordance with the rules given in the 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.
22、Publication as an International Standard requires approval by at least 75 % of 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 pat
23、ent rights. ISO 16826 was prepared by Technical Committee ISO/TC 135, Non-destructive testing, Subcommittee SC 3, Ultrasonic testing. BS EN ISO 16826:2014ISO 16826:2012(E) ISO 2012 All rights reserved vIntroduction This International Standard is based on EN 583-4:2002+A1:2003, Non-destructive testin
24、g Ultrasonic examination Part 4: Examination for discontinuities perpendicular to the surface. The following International Standards are linked. ISO 16810, Non-destructive testing Ultrasonic testing General principles ISO 16811, Non-destructive testing Ultrasonic testing Sensitivity and range settin
25、g ISO 16823, Non-destructive testing Ultrasonic testing Transmission technique ISO 16826, Non-destructive testing Ultrasonic testing Examination for discontinuities perpendicular to the surface ISO 16827, Non-destructive testing Ultrasonic testing Characterization and sizing of discontinuities ISO 1
26、6828, Non-destructive testing Ultrasonic testing Time-of-flight diffraction technique as a method for detection and sizing of discontinuities BS EN ISO 16826:2014BS EN ISO 16826:201411 Scope This International Standard defines the principles for tandem- and longitudinal-longitudinal-transverse (LLT)
27、wave examination for the detection of discontinuities perpendicular to the surface. The general principles required for the ultrasonic examination of industrial products are described in ISO 16810. A list of symbols and equations is given in ISO 16811. The tandem- or LLT-examination should be used f
28、or the detection of planar discontinuities with distance to the surface greater than 15 mm. This International Standard has been prepared for the examination of metallic ma-terials with a thickness between 40 mm and 500 mm with parallel or concentric surfaces. It can, however, be used for other mate
29、rials and smaller thickness provided special measures are taken. 2 Normative references The following referenced documents 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 docume
30、nt (including any amendments) applies. ISO 5577, Non-destructive testing Ultrasonic inspection Vocabulary ISO 16810, Non-destructive testing Ultrasonic testing General principles ISO 16811, Non-destructive testing Ultrasonic testing Sensitivity and range setting 3 Terms and definitions For the purpo
31、ses of this document, the terms and definitions given in ISO 5577 and EN 1330-4 apply. 4 Tandem examination 4.1 General The examination is normally carried out using two similar 45 angle probes, one probe operating as the transmitter and the other probe as receiver. For wall thicknesses greater than
32、 approximately 160 mm, probes with different transducer sizes are preferred in order to ensure approximately the same beam diameters in the examination zone. The use of probe angles other than 45 may be necessary to comply with particular geometrical conditions. Probe angles that give rise to mode c
33、onversions shall be avoided. INTERNATIONAL STANDARD ISO 16826:2012(E)Non-destructive testing Ultrasonic testing Examination for discontinuities perpendicular to the surface ISO 2012 All rights reserved EN 1330-4, Non-destructive testing Terminology Terms used in ultrasonic testing BS EN ISO 16826:20
34、142 The probes are located in a line with their acoustic axis in the same direction. In this way the sound beam from the rear probe will, after reflection from the opposite surface, intersect the sound beam from the front probe at the centre of the examination zone. Figure 1 shows the relationship b
35、etween the spacing of the probes (y) and the examination depth of the crosspoint (tm) and the height of the examination zone (tz). Key 1 Probe 1 d Material thickness 2 Probe 2 tmExamination depth 3 Examination zone y Probe distance a Projection distance tzHeight of examination zone Figure 1 Basic pr
36、inciple of tandem technique When examining objects with plane parallel surfaces the distance between the probes can be defined using the following equation: )(tan2mtdy = (1) for 45 )(2mtdy = (2) Scanning shall be performed in either of the following ways: both probes are moved along the surfaces wit
37、h a fixed distance (y). In this way only one examination zone is examined at a time, and the scanning shall be repeated with different probe distance until the complete examination volume has been examined; both probes are moved simultaneously, such that the sum of their distances from the required
38、plane of intersection, e.g. the vertical weld axis, remains constant, thereby scanning the full object thickness in one continuous movement. 4.2 Time base adjustment Basically all relevant echoes will appear at the same sound path distance, which corresponds to the V-path. Therefore, the adjustment
39、of the time base is not important. It is, however, recommended that the echo from the V-path is located at a fixed position e.g. eight scale divisions. ISO 16826:2012(E) ISO 2012 All rights reserved BS EN ISO 16826:201434.3 Setting of sensitivity The setting of sensitivity can be performed using the
40、 following reflectors: opposite surface, where the V-path echo is used as backwall echo; disk-shaped reflectors perpendicular to the scanning surface (flat-bottomed holes). The reflectors shall be located at the intersection of the beam axes; side drilled holes located at the intersection of the bea
41、ms and at the borders of the examination zones. 4.4 Determination of examination zones The division into equally sized examination zones ensures that the sensitivity throughout the thickness does not fall below a certain level. The height of the examination zones is calculated so that the sensitivit
42、y at the edges of the examination zones is not more than 6 dB below the sensitivity in the intersection point of the beam axes, see Figure 2. All dimensions in millimetres Key A Sound beam diameter d Material thickness tz Height of examination zone Figure 2 Examination zones The height of the examin
43、ation zone (tz) can be determined by using a reference block with reflectors in differentiated depths or calculated as follows based on the diameter of the direct beam and the largest sound path in the examination zone closest to the opposite surface (all dimensions in millimetres): effzcossin)mm 15
44、(D dt(2) for 45 effz)mm 15(2Dd twhere Deff effective transducer diameter. ISO 16826:2012(E) ISO 2012 All rights reserved BS EN ISO 16826:20144 The number of examination zones is calculated as follows: 3211mm30tzztz, =+= ntdn (3) The probe distance, y, see Figure 1, is adjusted for each examination z
45、one with the intersection of the beam axes in the centre of the zone. Alternatively, the width and number of the examination zones can be determined graphically using scale drawings of the calculated or measured 6 dB beam profiles. 4.5 DGS-diagram for tandem examination DGS-diagrams for tandem exami
46、nation may be derived from the general DGS-diagram or based on probe specific diagrams. The diagrams are prepared as shown in Figure 3. The mean value of the gain differences V1and V2are derived from the specific diagrams for the probes or from the general DGS diagram. These are used to establish a
47、distance amplitude curve (DAC) for specific tandem examinations, based on this disk-shaped reflector (DSR). Key DDSRDisk-shaped reflector S Sound path distance t Depth V Gain 1, 2 Probe 1, probe 2 3 Backwall Figure 3 Preparation of tandem DGS-diagram ISO 16826:2012(E) ISO 2012 All rights reserved BS
48、 EN ISO 16826:201454.6 Corrections of sensitivity Depending on the method used for sensitivity setting, corrections for transfer and attenuation losses may be applicable. In addition to this, compensation shall be made for the reduction of sensitivity that will occur at the edges of the examination
49、zone. Either 6 dB or the value measured on disk-shaped reflectors (flat-bottomed holes) at the border of the examination zones should be used. 4.7 Object with concentric surfaces The use of 45 angle probes is limited to d/D 0,04 for convex scanning surfaces and d/D 0,05 for concave scanning surfaces. Where applicable, the angles of incidence shall be changed to prevent mode conversions that can result in reduced sensitivity. The probe spacing (y) fo
