Frequency Flashcards
What sizing technique should be used to plot LAMINATIONS
EQUAL AMPLITUDE
What sizing technique should be used to plot POROSITY when using Straight-beam
MAX AMPLITUDE
When plotting CORROSION with Straight-Beam,
What technique should be used…
Plot from outside the Corrosion field, where full wall thickness exists, evidenced by a full height back wall indication
THEN
Move toward the Corrosion until a consistent reduction in Back-Wall Echo is first detected…MARK LEADING EDGE OF TRANSDUCER.
When plotting CORROSION with Straight-Beam,
What ALTERNATE technique may be used…
Starting with the Tx outside of the Corrosion,
MOVE TOWARD THE CORROSION UNTIL A 6dB DROP IN BWE…
MARK THE CENTER OF THE Tx.
When cleaning a scanning surface prior to testing,
What is the measured distance calculated from?
The full skip distance (Surface Distance) for the highest angle to be used (70*) + 1 inch for the heel of the wedge behind the BIP
What could cause ghost signals?
Too high PRF setting
Electrical short in the coaxial cable
What might cause a dead battery during the work shift of a UT inspector?
Poor planning
As the material being test becomes Thicker
The Tx Crystal should also become Thicker
TRUE
The Thicker the crystal,
The Lower the Frequency
Which provides better Penetration
Through Thick material
The thinner the material
The higher the Frequency
GENERALLY TRUE
A Thin Tx crystal provides a Higher Frequency
Which provides better Near Surface Resolution.
Be sure to consult the Project Specifications and Codes to be certain that you are working within the Frequency limitations of the referenced Code.
T or F
A broad band frequency provides better penetration
FALSE
A broad band frequency includes a wider range of frequency…both Lower & Higher Frequencies.
Unfortunately, the Higher Frequencies are more Attenuated…allowing LESS PENETRATION
