ISO INTERNATIONAL STANDARD 16826 First edition 2012-04-01 Non-destructive testing Ultrasonic testing Examination for discontinuities perpendicular to the surface Essais non destructifs- Controle par ultrasons Controle des discontinuités perpendiculaires a la surface Reference number ISO 16826:2012(E) @ISO 2012 py IHS under lic Not for Resale ISO 16826:2012(E) COPYRIGHTPROTECTEDDOCUMENT @SO2012 IsO's memberbody in the country of the requester. ISO copyright office Case postale 56 : CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland @IsO 2012-All rights reserved etworking permitted without license from IHS Not for Resale ISO 16826:2012(E) Contents Page Foreword .iv Introduction 1 Scope. 2 Normative references. 3 Terms and definitions 4 Tandem examination 4.1 4.2 Time base adjustment. 4.3 Setting of sensitivity ... 4.4 Determination of examination zones 4.5 DGS-diagram for tandem examination.. 4.6 Corrections of sensitivity .... 4.7 Object with concentric surfaces .. 5 LLT-examination. 5.1 5.2 Time base adjustment and determination of discontinuity depth .. 5.3 Setting of sensitivity ... 5.4 Determination of examination depth. 5.5 DGS-diagrams for LLT-examination.. 5.6 Correction of sensitivity .... Annex A (informative) Nomograms for determination of tandem distances for convex (Figure A.1) and concave (Figure A.2) scanning surface.... 12 Copyright International Organization far Standardizalon ghts reserved ili THS under ed without license from IHS Not for Resale