2013BS EN 15317:2013 Non-destructive testing. Ultrasonic testing. Characterization and verification of ultrasonic thickness measuring equipment
2007BS EN 15317:2007 Non-destructive testing - Ultrasonic testing - Characterization and verification of ultrasonic thickness measuring equipment
BS EN 15317:2013 Non-destructive testing. Ultrasonic testing. Characterization and verification of ultrasonic thickness measuring equipment was changed to KS F 4561-2013 Braille blocks for the visually impaired.