Which display type is characterized by a plot of signal amplitude versus time?

The A-scan display is characterized by a plot of signal amplitude versus time, making it a fundamental tool in ultrasonic testing. In this type of display, the horizontal axis represents time (or distance, when taking sound speed into account), while the vertical axis indicates the amplitude of the returned ultrasonic signal. This format allows the operator to observe the strength of the echoes received from various interfaces or discontinuities within the tested material.

The A-scan is particularly useful for evaluating single-point measurements and providing information about the depth and size of defects by analyzing peak amplitudes and their corresponding times of flight. This type of display is essential for understanding the characteristics of the material being tested, as it allows for an immediate visual interpretation of the data.

In contrast, the B-scan and C-scan displays provide two-dimensional and three-dimensional representations of data, respectively, often with a focus on mapping out defects or morphology within a given area, rather than the amplitude vs. time graph presented in an A-scan. These other display types are helpful for different applications but do not provide the same direct indication of signal amplitude relative to time that is found in the A-scan display.