Dashboard TOFD / Section 2: TOFD Theory / Chapter 3: Theory

A-Scan

A-Scan

Contrary to the conventional UT A-Scan, a TOFD A-Scan displays a non-corrected signal. This means:

  1. The positive and negative part of the signal are displayed
  2. The 0% amplitude is at the center of the screen with maximum positive amplitude at one edge of the screen and maximum negative amplitude at the other edge

Displaying both positive and negative peaks is very useful when looking for phase shifts.