Term
| what would be considered applications of ultrasonic techniques? |
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Definition
determination of a material's elastic modulus
study of a materials metallurgical structure
measurement of a material's thickness |
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Term
| what wave modes travel through liquid |
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Definition
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Term
| the acoustic impedance of a material is used to |
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Definition
| determine the relative amounts of sound energy coupled through and reflected at an interface |
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Term
| when angle beam contact testing a test piece, increasing the incident angle until the 2nd critical angle is reached results in |
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Definition
| the production of a surface wave |
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Term
| the crystal thickness and transducer frequency are related. The thinner the crystal: |
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Definition
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Term
| the random distribution crystallographic direction in alloys with large crystalline structure is a factor in determining |
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Definition
acoustic noise level
scattering of sound
selection of test frequency |
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Term
| what may result in a long narrow rod if the beam divergence results in a reflection from a side of the test piece before the sound wave reached the back surface? |
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Definition
| conversion from the longitudinal mode to shear mode |
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Term
| where does beam divergence occur |
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Definition
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Term
| as frequency increases in UT, the angle of beam divergence of a given diameter crystle does what? |
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Definition
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Term
| the ratio of velocity of sound in water compared to that for aluminum or steel is approximately? |
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Definition
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Term
| using the immersion method, a distance-amplitude curve (DAC) for a 3/4" diameter, 5-MHz search unit shows the highpoint of the DAC at the 1-1/2" block. One day later the high point of the DAC for the same search unit is at the 3/4" block assuming calibration has not changed, this would indicate that the search unit: |
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Definition
is becoming defective
and
has the beam of a smaller search unit |
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Term
| on an A-scan display, what represent the intensity of a reflected beam? |
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Definition
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Term
| which best describes a typical display of a crack whose major surface is perpendicular to the ultrasonic beam? |
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Definition
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Term
| a primary purpose of a reference standard is: |
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Definition
| to provide a guide for adjusting instrument controls to reveal discontinuities that are considered harmful to the end use of the product |
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Term
| compensation for the variation in echo height related to variations in discontinuity depth in the test material is known as |
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Definition
| distance amplitude correction |
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Term
| this is a reference reflector that is not dependent on beam angle |
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Definition
| a side drilled hole which is parallel to the plate surface and perpendicular to the sound path |
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Term
| a smooth flat discontinuity whose major plane is not perpendicular to the direction of sound propagation may be indicated by |
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Definition
an echo amplitude comparable in magnitude to the back surface reflection
a complete loss of back surface reflection
an echo amplitude larger in magnitude than the back surface reflection |
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Term
| using a pulse-echo technique, if the major plane of a flat discontinuity is oriented at some angle other than perpendicular to the direction of sound propagation, the result may be |
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Definition
| loss or lack of a received discontinuity echo |
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Term
| a set of standard reference blocks with the same geometrical configuration and dimensions other than the size of the calibration reflectors e.g. flat bottom holes is called a set of |
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Definition
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Term
| what controls the voltage supplied to the vertical deflection plates of the CRT in an A-scan set UT set up? |
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Definition
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Term
| attenuation is a difficult quantity to measure accurately, particularly in solid materials, at the test frequencies normally used. The overall result usually observed includes other loss mechanisms which can include:? |
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Definition
beam spread
couplant mismatch
test piece geometry |
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Term
| the vertical linear range of a test instrument may be determined by obtaining ultrasonic responses from: |
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Definition
| a set of area-amplitude reference blocks |
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Term
| large grains in metallic test specimen will usually result in |
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Definition
decrease of lose of back surface reflection
large "hash"or noise indications
Decrease in penetration |
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Term
| The total energy losses occurring in all materials is called |
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Definition
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Term
| the electronic circuitry that allows selection and processing of only those signals relating to discontinuities that occur in specific zones of a part is called |
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Definition
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Term
| the time duration of the transmitted pulse is referred to as |
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Definition
| the pulse length or pluse width |
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Term
| number of pulses in a given period of time is |
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Definition
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Term
| the component that coordinates the action and time of other components is called |
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Definition
| synchronizer, clock or timer |
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Term
| wich calibration block is normally used for weld inspection to set sensitivity |
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Definition
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Term
| most basic pulse-echo UT instruments use what presentation |
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Definition
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Term
| not an advantage of contact ultrasonic search units (probes) adapted with lucite shoes |
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Definition
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Term
| advantages of contact ultrasonic search units (probes) adapted with lucite shoes |
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Definition
eliminates most of crystal wear
permits adaptation to curved surfaces
allows ultrasound to enter a part's surface at oblique angles |
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Term
| time duration of the transmitted pulse is called |
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Definition
| pulse length or pulse width |
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Term
| # of pulses produced by an instrument in a given period of time is |
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Definition
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Term
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Definition
| a diagram in which the entire circuit stage or sections are shown by geometric figures and the path of the signal or energy by lines and/or arrows. |
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Term
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Definition
In fig 1, assuming a uniform beam pattern, what relationship would you expect to exist between the amplitudes of reflected laminar signals at position A and B
2 to 1 |
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Term
| In the far field of uniform ultrasonic beam, sound intensity is ___________ the beam centerline |
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Definition
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Term
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Definition
Fig 2 illustrates a contact test on an 8-inch aluminum block. A discontinuity is located 6 inches from the front surface. The screen representation for this is shown to the right What does indication D represent?
First discontinuity indication |
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Term
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Definition
What are transducers A, C, and D measuring
A- exit point (think thickness)
C- sensitivity Calibration
D- check that angle of transducer is right
name
IIW block |
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Term
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Definition
What is the name of this block?
Distance sensitivity calibration block (DSC)
What are the reflectors for the transducer pointed toward the small radius?
1,3,5 |
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Term
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Definition
This block can be use to?
Perform a L-wave distance calibration
Preforme a S-wave distance calibration
Determine wedge angle
What is the name of this block?
Miniature angle beam |
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Term
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Definition
What is the calibration block type?
IIW Type II |
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Term
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Definition
Fig B is being used to?
Check the beam angle |
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Term
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Definition
Fig C is being used to?
Calibrate the time base for an angle probe |
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Term
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Definition
Fig E is being used to?
Measure the probe dead zone |
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Term
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Definition
Fig G is being used to?
Set sensitivity |
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Term
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Definition
Fig D is being used to?
Measure beam angle |
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Term
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Definition
Fig F is being used to?
Check probe resolution |
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Term
| 1st critical angle formula |
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Definition
2nd sin(V1L/V2L)=1st crit angle
L=longitudinal |
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Term
| 2nd critical angle formula |
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Definition
| 2nd sin(V1L/V2T)= 2nd crit angle |
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Term
| what wave moves in elliptical motion |
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Definition
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Term
| angle of incidence formula |
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Definition
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Term
50/50 sizing method
aka 6dB reduction |
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Definition
50% = 6dB
after 50% reduction edge of crack is in center of beam profile
flaw must be > or = beam |
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Term
| when is tip diffraction more commonly used |
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Definition
small cracks
good for cracks on ID of pipe work of pressure vessels |
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Term
| what is the phase relationship of the tip signal |
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Definition
tip diffraction from upper flaw extremities will be generated in the same phase as the back wall response
the phase may be either negative or positive
this is dependant upon electrical connections and acoustic impedance interfaces |
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Term
| what are the most common errors of id creep/tip difraction and why? |
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Definition
| confusing, messy screen flaws close together will make screen more messy positioning of the flaw due to combinations of acoustic velocity from ce1 and ce2 signals T-waves can convert to L-waves responses can be low in amplitude not much higher then 2 to 4 times the baseline noise |
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Term
| we see Ce2 when crack is at least what % of thickness |
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Definition
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Term
| we see Ce1 when crack is at least what % of thickness |
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Definition
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Term
| we see L-wave when crack is at least what % of thickness |
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Definition
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Term
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Definition
At the critical angle of incidence,
inhomogeneous compression wave,
travels along the interface
decays exponentially with depth from the interface. |
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Term
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Definition
When sound travels through a medium, its intensity diminishes with distance.
In idealized materials, sound pressure (signal amplitude) is only reduced by the spreading of the wave.
Natural materials, however, all produce an effect which further weakens the sound.
This further weakening results from two basic causes, which are scattering and absorption.
The combined effect of scattering and absorption is called attenuation |
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Term
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Definition
Caused by preferential grain direction EG. Cast stainless, SS welds, inc 625 welds
Velocity can vary and will depend on the crystal direction/elastic Modulus |
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Term
| several types of sound waves that travel through solids |
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Definition
Longitudinal Waves/Compression Waves
Shear Waves/Transverse Waves
Lamb Waves/Plate Waves
Surface Waves/Rayleigh Waves |
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Term
| Properties of Longitudinal Waves |
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Definition
Travels in all medium
Maximum velocity
Particles vibrate parallel to wave direction
Has maximum penetration power
Least attenuation
Used in immersion testing
Used mainly for straight beam inspection
for detection of lamellar flaws |
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Term
| Properties of Surface Waves |
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Definition
Particle Vibration: Elliptical Motion
Maximum depth of penetration: 1waveleangth
Cannot negotiate a sharp edge If the surface has substances like grease, oil etc. surface wave gets easily dampened.
Is generated by angulating the incident angle at the second critical angle.
Very sensitive to surface flaws
Velocity of surface wave is approximately 0.9 times of that of shear wave. |
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Term
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Definition
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Term
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Definition
Source of short high energy bursts of electrical energy
triggerd by timer |
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Term
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Definition
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Term
| The block is much smaller and lighter than the IIW block but performs many of the same functions. |
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Definition
| Miniature Angle-Beam or ROMPAS Calibration Block |
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Term
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Definition
| have a constant taper over the desired thickness range. |
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Term
| Step and Tapered Calibration Wedges |
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Definition
| Step and tapered calibration wedges come in a large variety of sizes and configurations. Step wedges are typically manufactured with four or five steps but custom wedges can be obtained with any number of steps. Tapered wedges have a constant taper over the desired thickness range. |
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Term
| how many Distance/area amplitude correction blocks typically in a set |
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Definition
10
they typically come as a ten-block set |
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Term
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Definition
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Term
| the difrence between sheer and longatudinal waves (pic) |
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Definition
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Definition
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Definition
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