Non-Destructive Testing (NDT) Practice Test

What instrument feature was adjusted to measure the thickness of a .250” thick piece of aluminum during inspection?

1. Gain

2. Range

3. Gate

4. Frequency

The correct answer is: Gate

The appropriate adjustment for measuring the thickness of a .250” thick piece of aluminum during inspection is the range feature of the instrument. Range settings on non-destructive testing equipment allow the operator to select the appropriate measurement scale based on the expected thickness of the material being tested. When inspecting materials of known thickness, such as aluminum, setting the correct range ensures that the instrument can accurately measure and interpret the reflected signals returned from the material. This is essential for obtaining precise and reliable thickness readings. In contrast, while gain settings are related to the amplification of the signal and may enhance visibility, they do not directly determine the measurement range that is suitable for the thickness in question. The gate feature is used to select specific time windows for receiving signals, making it less relevant to merely determining thickness through range setting. Frequency adjustments typically pertain to ultrasound testing and may affect resolution and penetration, but they do not specifically address the thickness measurement like the range setting does.