168611 ⎘
Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object; Analysing solids; Visualisation of the interior, e.g. acoustic microscopy; Display arrangements, e.g. colour displays synchronised with scanning, e.g. in real-time Cathode-ray tube displays