Plotting system for sound isobars - produced by test head in non-destructive testing by sampling in X and Y planes

摘要

The plotting system plots sound isobars produced by a sound test head used for non-destructive testing. The acoustic pressure field is sampled over an XY plane at right angles to the head's axis using a reflector. The XY plane is scanned in lines and the echo signal resulting from the field is converted into a voltage proportional to echo intensity and sent through a number of electrical window discriminators. The resulting signal is registered as a point on an isobar.