Illustrate the c-scan presentation of test specimen?
C-mode:
The C-scan presentation gives a plan-type (2D) view of the location and size of test specimen characteristics. The plane of the figure is parallel to the scan pattern of the transducer. The C-scan presentations are generated along with an automated data acquisition system, as like a computer controlled immersion scanning system. Characteristically, a data collection gate is established onto the A-scan and the amplitude or the time-of-flight of the signal is recorded at ordinary intervals as the transducer is scanned over a test piece. The planar images can be produced on flat parts by tracking data to X-Y position, or onto cylindrical parts through tracking axial and angular position. For a conventional ultrasound, the mechanical scanner along with encoders is utilised to track the transducer's coordinates to the needed index resolution
The relative signal amplitude or the time-of-flight is exhibited as a shade of gray or a colour (as b-mode representation) for all of the positions where data was recorded. This C-scan presentation gives an image of the features which reflect and scatter the sound into and on the surfaces of the test piece.
Assume that the test piece has a discontinuity as demonstrated in figure given below. The top view of the piece demonstrating the direction of movement of the transducer that is the scan pattern and the image constructed throguh plotting the brightness of the reflections at each of which scan points is also demonstrated.