ISO INTERNATIONAL STANDARD 18490 Firstedition 2015-06-01 Non-destructive testing Evaluation of vision acuity of NDT personnel Essaisnondestructifs-Evaluation deI'acuitevisuelledupersonnel END Referencenumber ISO18490:2015(E) ISO Intemational Organization for Standardization @IS02015 ng Instituteof Standardization5956617 itted without licensefrom IHS IS0 18490:2015(E) COPYRIGHTPROTECTEDDOCUMENT IS02015,Published inSwitzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8. CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +4122 749 09 47 copyright@iso.org www.iso.org Intemationaibr PrganizationforStandardization etworking permitted without license from IHS NotforResale, 2015/8/705:27:49 IS018490:2015(E) Contents Page Foreword ..iv Introduction.. 1 Scope.. 2 Normativereferences 3 Terms and definitions 4 Chart print quality ..1 5 Health and safety. .2 6 Personneladministeringthetest. 7 Test charts .2 8 Test procedure .2 8.1 General .2 8.2 Illumination level. .2 8.3 Eyetochartdistance .3 8.4 Eyewear... .3 8.5 Candidate's responses .3 8.6 The test. .3 9 Acceptancelevel .3 Annex A (normative)Format and size of the optotypes ..4 AnnexB (normative)Spacingoftheoptotypes .1 Annex C (informative) Example test chart (Notto scale) .8 ntemationalganizatin5All rights reserved iii see=Zhejiang Institute of Standardization 5956617 thout license from IHS