A-scan - the information is contained in the way that the acoustic wave is reflected from the specimen. This time of flight information is depending upon the depths of the sample feature.

A digital waveform on the user interface screen displays the arriving echoes . This quantitative time distance measurement (echo- time) display is used to set electronic gates to select the depth range of view. If more than one gate is placed (G-scan) multiple images are displayed in the monitor screen.