UTL1 Flashcards
What is the equation for wavelength
Wavelength = V / F
What is the smallest consistently detectable sized discontinuity
1/2 wavelength
In regards to Frequency: When the frequency is increased What is the resulting affect to the wavelength?
The wavelength is decreased
In regards to Frequency: What must be done to increase sensitivity?
Increase the frequency; Hence you have reduced the wavelength; Thereby reducing the minimum detectable discontinuity; Therefore, increasing the sensitivity
In regards to Frequency: What must be done to increase resolution?
Increase frequency will reduce the wavelength; Thereby increasing resolution.
Regarding FPADS CRYN Define the F?
Frequency
Regarding FPADS CRYN Define P?
Penetration
Regarding FPADS CRYN Define A?
Attenuation
Regarding FPADS CRYN Define D?
Divergence
Regarding FPADS CRYN Define S?
Sensitivity
Regarding FPADS CRYN Define C?
Crystal Thickness
Regarding FPADS CRYN Define R?
Resolution
Regarding FPADS CRYN Define Y
Wavelength… I know it doesn’t appear as such, however the qwerty keyboard does not have a wavelength symbol.
Regarding FPADS CRYN Define N?
Near Field
Using the memory tip WaVeForm What is the relevant equation?
W = V/F
If increased Sensiivity is desired, what change is transducer Frequency should be made?
Increase the transducer Frequency
Wavelength x Frequency =
Velocity
When performing UTT on externally corrodes material, The best selection of couplant in regards to viscosity would be?
HIGH VISCOSITY A thick couplant could better fill in voids at the Tx to scan surface interface.
When performing UTT on externally corrodes material, The best selection of couplant in regards to viscosity would be?
HIGH VISCOSITY A thick couplant could better fill in voids at the Tx to scan surface interface.
Which Tx would best penetrate an 18.00 inch thick kiln roller 1 MHz 2.25 MHz 5 MHz 10 MHz
1 MHz Low Frequency Higher Penetration
When calculating the Remaining Wall Thickness (RWT) after manually taking PIt Depth Gauge readings; The PDG reading should be subtracted from the Tnom or AWT? What additional step should be taken?
AWT Take a UTT Wall Thickness reading using a pencil probe Tx as necessary to verify Internal Corrosion
What is the purpose of a couplant at the Tx to test surface interface?
To displace the AIR at the Interface thus reducing the Accoustic
What formula is used to calculate the relationship between the incident angle and the refracted angle?
SNELL’S LAW
Is the incident angle EQUAL TO The Refracted Angle OR The Reflected Angle
The Reflected Angle
Between mode types (Longitudinal OR Transverse) Which mode has the higher Velocity
Longitudinal Wave mode has a Velocity approximately 2 X that of Transverse within a given material
Which wave mode is Refracted from the material at the 1st Critical Angle?
Longitudinal Wave
At the 1st Critical Angle what happens to the Longitudinal Wave?
It becomes an OD Creep wave
At the first Critical Angle what happens to the Transverse Wave?
It becomes LONELY, as it is the only remaining wave mode within the material
Beyond the 1st Critical Angle, yet before the 2nd Critical Angle, What happens to the Longitudinal Wave?
It is 100% Reflected away from the material at the material interface
What happens at the 2nd Critical Angle?
The Transverse Wave is Refracted to the material surface and is converted into a Raleigh Wave (Surface Wave)
What wave mode exists at the 2nd Critical Angle?
A Surface Wave (Raleigh)
Within a given material: What is the Velocity of a Surface-Wave when compared to a Shear-Wave?
Approx. 9/10th 0.9 90%
In regards to Tx manufacturing: What is the benefit to producing a HIGHLY DAMPENED TRANSDUCER?
It stops the ringing sooner Therefore resulting in a SHORTER PULSE LENGTH & INCREASED NEAR SURFACE RESOLUTION
Regarding Transducer (Tx) manufacturing: Which crystal element THICKNESS is needed for high frequency production?
A THIN CUT crystal
A Transducer crystal is cut THICK and AGAINST the grain What would be the intended use for such a crystal?
For the production of LOW FREQUENCY SHEARWAVES
A Transducer crystal is cut THIN and PARALLEL to the grain What would be the intended use for such a crystal?
For the production of HIGH FREQUENCY L-WAVES
What type of energy exists within the coaxial cable?
ELECTRICAL ENERGY
What type of energy exists within the material being tested with UT?
MECHANICAL ENERGY
What converts Electrical energy into Mechanical energy & vise-versa?
A PIEZOELECTRIC CRYSTAL
At what FREQUENCY is sound considered to become ULTRASOUND
20,000 Hertz (Hz)
What is defined as 1 cycle per second
HERTZ
How many cycles per second are produced by a 5 MHz Tx
5,000,000
What is the Frequency of a Transducer that produces 2,250,000 cycles per second
2.25 MHz
Screen Range = 5.0 inch Screen graticle grid has 10 divisions What is the material thickness of the Back-Wall Echo (BWE) is at 3.0?
1.50” T material
What is the equation for Snell’s Law
SIN 1 = VEL 1 —– ——- SIN 2 VEL 2
What is the Refracted Angle of L-Waves at the 1st Critical Angle?
90*
Which Critical Angle is represented by 90* Refraction of the Transverse Waves?
2nd Critical Angle
How is the Beam Spread affected when Frequency is Increased?
Beam Spread is DECREASED when Frequency is INCREASED
What Frequency should be selected to produce a SHORTER NEAR FIELD
LOW FREQUENCY
What is a negative side affect of using high sensitivity probes?
Increased Attenuation
What type of probe would be best for detecting SMALL, NEAR SURFACE DISCONTINUITIES IN THIN MATERIAL?
HIGH FREQUENCY DUAL ELEMENT
