1、BSI Standards PublicationBS EN ISO 18490:2015Non-destructive testing Evaluation of vision acuity ofNDT personnelBS EN ISO 18490:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO18490:2015.The UK participation in its preparation was entrusted to TechnicalC
2、ommittee WEE/46, Non-destructive testing.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards In
3、stitution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 81370 2ICS 03.100.30; 11.040.70; 19.100Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 June
4、 2015.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 18490 June 2015 ICS 03.100.30; 11.040.70; 19.100 English Version Non-destructive Testing - Evaluation of vision acuity of NDT personnel (ISO 18490:2015) Essais non destructifs - Evalua
5、tion de lacuit visuelle du personnel END (ISO 18490:2015) Zerstrungsfreie Prfung - Bestimmung der Sehfhigkeit von ZfP-Personal (ISO 18490:2015) This European Standard was approved by CEN on 12 March 2015. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the c
6、onditions for giving this European Standard the status of a national standard without 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 ex
7、ists in three official versions (English, French, German). A version in any other language 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 s
8、tandards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia,
9、 Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2015 CEN All rights of exploitation in any form and by any means res
10、erved worldwide for CEN national Members. Ref. No. EN ISO 18490:2015 EBS EN ISO 18490:2015EN ISO 18490:2015 (E) 3 Foreword This document (EN ISO 18490:2015) has been prepared by Technical Committee CEN/TC 138 “Non-destructive testing“, the secretariat of which is held by AFNOR, in collaboration with
11、 Technical Committee ISO/TC 135 “Non-destructive testing“. 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 December 2015, and conflicting national standards shall be withdrawn at the latest by Dec
12、ember 2015. 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. According to the CEN-CENELEC Internal Regulations, the national standards
13、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, Italy, Latvia, Lithuania, Luxembo
14、urg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 18490:2015 has been approved by CEN as EN ISO 18490:2015 without any modification. BS EN ISO 18490:2015ISO 18490:2015(E)Forewo
15、rd ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Chart print quality 15 Health and safety 26 Personnel administering the test 27 Test charts . 28 Test procedure 28.1 General . 28.2 Illumination level 28.3 Eye to chart distance 38.4 Eyewear . 38.5 Candidates response
16、s 38.6 The test 39 Acceptance level 3Annex A (normative) Format and size of the optotypes . 4Annex B (normative) Spacing of the optotypes . 7Annex C (informative) Example test chart (Not to scale) 8 ISO 2015 All rights reserved iiiContents PageBS EN ISO 18490:2015ISO 18490:2015(E)ForewordISO (the In
17、ternational Organization 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 h
18、as been established 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
19、 standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in ac
20、cordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).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. Deta
21、ils of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an en
22、dorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword Supplementary information .ISO 18490 was pre
23、pared by European Committee for Standardization (CEN) in collaboration with ISO/TC 135, Non-destructive testing, SC 7, Personnel Qualification, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).iv ISO 2015 All rights reservedBS EN ISO 18490:2015ISO 1849
24、0:2015(E)IntroductionStandards for NDT Personnel qualification and certification require that the visual acuity of inspection personnel is verified as being appropriate to their function. By meeting the near vision acuity level defined in this International Standard, such requirements of ISO 9712 an
25、d EN 4179 will be met. The purpose of this International Standard is to provide a detailed, standardised procedure for the evaluation of near vision acuity for such personnel under defined lighting conditions.The test is not medical in nature and is intended to objectively ensure adequate near visio
26、n perception without reliance on reading ability or text identification. Because it is extremely difficult to demonstrate any equivalency in near vision tests, this International Standard has been prepared in order that an international system may be used without any need to demonstrate equivalence
27、and is the recommended method of determining near vision acuity for NDT Personnel. ISO 2015 All rights reserved vBS EN ISO 18490:2015BS EN ISO 18490:2015Non-destructive testing Evaluation of vision acuity of NDT personnel1 ScopeThis International Standard specifies the form of the optotype, the qual
28、ity requirements for the chart, the test procedure, and the acceptance level for near vision acuity of NDT personnel. It also addresses the qualification requirements for personnel permitted to carry out the test.This International Standard only addresses near vision acuity under defined conditions
29、similar to those encountered during routine NDT inspection. It does not address an individuals overall visual acuity and users are advised to consider the need for a general eye examination by specialist medical personnel to ensure general vision acuity is appropriate for job function.This Internati
30、onal Standard does not address colour vision requirements.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the lates
31、t edition of the referenced document (including any amendments) applies.ISO 9712, Non-destructive testing Qualification and certification of NDT personnelEN 41791)Aerospace series Qualification and approval of personnel for non-destructive testing3 Terms and definitionsFor the purposes of this docum
32、ent, the terms and definitions given in ISO 9712 and EN 4179 and the following apply.3.1optotypeE shaped character of defined proportions and of various sizes that are used to verify near vision acuity3.2eyewearany form of lens or protective transparent material placed or used between the human eye
33、and the work piece during routine NDT inspection operations4 Chart print qualityIt is recognized that charts produced locally will have varying print quality and resolution. The chart design, including the two separate blocks of characters, and the procedure has been developed to ensure that meeting
34、 the defined level will demonstrate compliance. Failure to meet the defined level of acuity, in some cases, may be due to the quality of the test chart produced. Care should be exercised to ensure that the quality of the test chart is appropriate and where personnel fail to meet the required level,
35、the quality of the chart should be reviewed before declaring that an individual has inadequate near vision.1) Under a Memorandum of Understanding, this is identical to NAS 410: Certification and Qualification of Non destructive Test Personnel.INTERNATIONAL STANDARD ISO 18490:2015(E) ISO 2015 All rig
36、hts reserved 1BS EN ISO 18490:2015ISO 18490:2015(E)5 Health and safetyCare shall be exercised when measuring or verifying the eye to chart distances.6 Personnel administering the testPersonnel administering the near vision acuity test shall be trained and familiar with the requirements before admini
37、stering this test and be designated by a Level 3. Such designation (including Level 3 self-designation) shall be made in writing and form as part of the formal records for that individual.Medical personnel including optometrists are not exempt from this requirement.7 Test chartsTest charts shall be
38、prepared in accordance with this International Standard. Charts shall be printed in black ink on white paper of an adequate quality and using equipment that ensures the print quality is suitable for the purpose. Charts shall be printed in black ink on white paper using equipment that ensures the pri
39、nt quality is suitable for the purpose. The printing equipment and the paper used shall be of an adequate quality for the purpose. This shall be verified practically by using magnification. The two blocks of optotypes (see Annex A) have been developed to accommodate the different types of printing e
40、quipment commonly encountered. The block which prints best shall be used. This can be determined under good lighting conditions using approximately 10 magnification. Inspect lines 9 and 10 and verify that the lines forming the limbs of the E characters on line 9 are all continuous and of an even app
41、earance. There shall not be any spread of the print material such that the gaps between the limbs are not visible. Line 10 characters may not all be perfectly formed due to the very small size and since it is not necessary to distinguish this line for compliance, the quality of this line does not fo
42、rm part of the acceptance criteria for the chart. It is, however, required that the overall shape of each optotype shall be discernible under magnification with the limbs and gaps being evident.The size of the optotype is important and the prepared charts include size verification marks. Printed cha
43、rts shall be verified to be the correct size by measurement. The annotated 250 mm distance between the defined marks shall be measured and shall not be less than 245 mm nor be more than 255 mm. Printing errors could affect vertical and horizontal scaling differently; therefore, before use, it shall
44、be verified that the basic shape of the individual optotype characters is square. This may be verified on the larger characters.Prepared charts shall comprise two blocks each having 10 lines of 5 optotypes. The height of each line, h, in mm, shall be as shown in Table A.1 and the spacing of the opto
45、types shall be as shown in Annex B. Each individual optotype shall be randomly orientated by rotating by a multiple of 90. There shall be no other printing or marking within or near to the optoptype blocks. An example chart is shown in Annex C. The actual chart to be administered to a candidate shal
46、l not be made available to that person prior to the test. A number of charts with different sequences of optotypes shall be used to ensure objective testing. Demonstration charts may be provided to show what will be required during the test.8 Test procedure8.1 GeneralPrior to the test being carried
47、out, it is necessary to ensure that properly prepared charts of verified quality are available. Tests shall be administered at a pace and in a manner that puts the candidate at ease.8.2 Illumination levelThe test shall be administered under controlled lighting conditions. Visible, white light, minim
48、um 500 lx, maximum 750 lx shall be used to evenly illuminate the chart. This shall be measured at the position of the chart using a calibrated visible light meter. Some ambient light in the surrounding area may be beneficial 2 ISO 2015 All rights reservedBS EN ISO 18490:2015ISO 18490:2015(E)but this
49、 should be lower than the test level. Higher levels of background may adversely affect results. Spurious light sources, bright objects, etc. should not be present within the field of view of the candidate.8.3 Eye to chart distanceThe chart shall be positioned perpendicular to the line of sight on a flat surface and the candidate shall move towards the chart to the test distance of 400 25 mm. At no time shall the candidate be permitted to get closer to the chart. A ruler or gauge stick may be used to verify the test distance; while traceable cali
