Ultrasonic Testing Flashcards
7 cards from real NDT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Ultrasonic Testing flashcards as text
What is the primary purpose of a couplant in ultrasonic testing?
Answer: To eliminate the air gap between the transducer and test material
Couplants fill the air gap between the transducer and material surface, enabling efficient transfer of ultrasonic energy since air is a poor acoustic conductor.
In ultrasonic testing, what does 'beam spread' refer to?
Answer: The divergence of the ultrasonic beam as it travels through a material
Beam spread is the natural divergence of an ultrasonic beam as it travels away from the transducer, which affects lateral resolution and coverage area.
Which ultrasonic testing method uses two separate transducers — one for sending and one for receiving?
Answer: Pitch-catch technique
The pitch-catch (or through-transmission) technique uses separate transmitter and receiver transducers, allowing detection of flaws that might not produce strong reflections.
What is the 'near field' (Fresnel zone) in ultrasonic testing?
Answer: The region close to the transducer where sound pressure varies irregularly
The near field (Fresnel zone) is the region close to the transducer face where constructive and destructive interference cause irregular sound pressure variations.
When performing angle beam UT on a weld, what is the 'skip distance'?
Answer: The surface distance traveled for one complete V-path (down and back up)
Skip distance is the surface distance covered in one full V-path of an angle beam, from entry point to where the beam returns to the surface after reflecting off the back wall.
Which material property most significantly affects ultrasonic attenuation?
Answer: Grain size and structure
Coarse grain size scatters ultrasonic waves, greatly increasing attenuation and making inspection of coarse-grained materials like cast iron more difficult.
In immersion ultrasonic testing, why is a water column maintained between the transducer and test piece?
Answer: To provide a consistent, bubble-free couplant path and allow precise beam angle control
The water column acts as an acoustic couplant and, combined with transducer angle adjustment, allows precise control of the refracted beam angle entering the test piece.