DIN EN ISO 16826:2014-06

This International Standard defines the principles for tandem- and longitudinal-longitudinal-transverse (LLT) 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 for 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 materials with a thickness between 40 mm and 500 mm with parallel or concentric surfaces. It can, however, be used for other materials and smaller thickness provided special measures are taken. 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 testing" the secretariat of which is held by AFNOR (France). The responsible German body involved in its preparation is Working Committee NA 062-08-23 AA "Ultraschallprüfung" ("Ultrasonic testing") at DIN Standards Committee Materials Testing (NMP).