UT 263 CARDS HAROLD BENNETT Flashcards
Ultrasonic Testing
“100,000 cycles per second” can be written:
100 kilohertz
“25 million cycles per second” can also be stated as:
25 megahertz
A smooth flat discontinuity whose major plane is not perpendicular to the direction of sound propagation may be indicated by:
1. An echo amplitude comparable in magnitude to the back surface reflection.
2. A complete loss of the back surface reflection.
3. An echo amplitude larger in magnitude than the back surface reflection.
All of the above.
A 25-megahertz search unit would most likely be used during:
IMMERSION TESTING
A 45 degrees shear angle beam transducer produces a wave in the metal which is polarized:
1. PERPENDICULAR TO THE DIRECTION OF PROPAGATION and
2. AT 45 DEGREE TO THE ENTRY SURFACE.
A B-scan display shows the relative:
DISTANCE A DISCONTINUITY IS FROM THE TRANSDUCER and
ITS LENGTH IN THE DIRECTION OF TRANSDUCER TRAVEL
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 is called a:
BLOCK DIAGRAM
A disadvantage of using natural quartz crystals in a search unit is that:
It is the least effective generator of ultrasonic energy of all commonly used materials.
A discontinuity is located having an orientation such that its long axis is parallel to the sound beam. The indication from such a discontinuity will be:
SMALL IN PROPORTION TO THE LENGTH OF THE DISCONTINUITY.
A discontinuity that occurs during the casting of molten metal which may be caused by the splashing, surging, interrupted pouring, or the meeting of two streams of metal coming from different directions is called:
A COLD SHUT
**Cold shut is a defect in welding or casting **
A grouping of a number of crystals in one search unit, with all contact surfaces in the sample plane, and vibrating in phase with each other to act as a single transducer is called a:
Crystal mosaic
A hole produced during the solidification of metal due to escaping gases is called:
A blow hole
A longitudinal ultrasonic wave is transmitted from water into steel at an angle of 5 degrees from the normal. In such a case the refracted angle of the transverse wave is:
Less than the refracted angle of the longitudinal wave.
A material used between the face of a search unit and the test surface to permit or improve the transmission of ultrasonic vibrations from the search unit to the material being tested is called:
A couplant
A plan view display or recording of a part under examination is called:
A C-scan display.
A C-scan is one of the most sophisticated ways to view ultrasonic testing data. It is a three-dimensional representation of the material thickness plotted over position both horizontally and vertically. In essence, C-scans are visual maps that reveal patterns of degradation in the asset.
A point, line, or surface of a vibrating body marked by absolute or relative freedom from vibratory motion is referred to as:
A node
A quartz crystal cut so that its major faces are parallel to the Z and Y axes and perpendicular to the X axis is called:
A X-cut crystal
A screen pattern containing a large number of low-level indications (often referred to as “hash”) could be caused by:
Coarse grained material
A search unit containing three or more individual transducer elements is often referred to as a:
Mosaic transducer
A search unit with a frequency greater than 10 MHz will most likely be used during:
An immersion test
A second name for Rayleigh waves is:
Surface waves
Rayleigh waves are also known as Lamb waves, or surface waves
A separate time base line imposed on the viewing screen of some ultrasonic testing instruments that permits measurement of distances is often referred to as:
A marker
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:
Area/Amplitude Standards.
A short burst of alternating electrical energy is called:
A pulse
A special scanning device with the transducer mounted in a tire- like container filled with couplant is commonly called;
A wheel search unit
A term used in ultrasonics to express the rate at which sound waves pass through various substances is:
Velocity
A term used to describe numerous small indications on the cathode ray tube screen resulting from test part structure, numerous small discontinuities or both is often referred to as:
Multiple back reflections
A term used to describe the ability of an ultrasonic testing system to distinguish between the entry surface response and the response of discontinuities near the entry surface is:
Resolution
A test method employing two separate search units on opposite surfaces of the material being tested is called:
Through-transmission testing
A test method in which the parts to be inspected are placed in a water bath or some other liquid couplant is called:
Contact testing
A type of data presentation most likely to be used with a high speed automatic scanning system is:
A C-scan presentation.
Acoustic energy propagates in different modes. Which of the following represents a mode?
1. Longitudinal wave
2. Shear wave
3. Surface wave
4. All of the above
Acoustic velocities are primarily described by:
1. DENSITY
2. ELASTICITY
3. both A and B
Acoustical lenses are commonly used for contour correction. When scanning the inside of a pipe section by the immersion method, which of the following lens types would be used?
Convex
All other factors being equal, which of the following modes of vibration has the greatest velocity?
Longitudinal wave
An advantage of using a ceramic transducer in search units is that:
It is one of the most efficient generators of ultrasonic energy.
An advantage of using lithium sulfate in search units it that:
It is one of the most efficient receivers of ultrasonic energy.
An amplitude type gate is necessary for all:
Automatic examinations.
An A-scan CRT display which shows a signal both above and below the sweep line is called a:
RF display
An electron tube in which a beam of electrons from the cathode is used to reproduce an image on a fluorescent screen at the end of the tube is referred to as:
A cathode ray tube
An ultrasonic test using a straight beam contact search unit is being conducted through the thickness of a flat part such as a plate. This test should detect:
Laminar-type flaws with major dimensions parallel to the rolled surface.
An ultrasonic testing instrument that displays pulses representing the magnitude of reflected ultrasound as a function of time or depth of metal is said to contain:
An A-scan presentation.
The A-Scan is a one-dimensional presentation of time versus the amplitude on the UT machine screen. It shows the existence of flaws (if any present during scanning), and their position, and also gives an estimate of their sizes.
An ultrasonic testing technique in which the transducer element is not parallel to the test surface is called:
Angle beam testing
Another name for a compressional wave is:
Longitudinal wave
Another name for Fresnel Zone is:
Near Field
As frequency increases in ultrasonic testing, the angle of beam divergence of a given diameter crystal:
Decreases.
As frequency increases in ultrasonic testing, the angle of beam divergence of a given diameter crystal:
Decreases
As the grain size increases in a material, its principal effect in ultrasonic testing is on:
The attenuation.
As the impedance ratio of two dissimilar materials increases, the percentage of sound coupled through an interface of such materials:
Decreases.
As the radius of curvature of a curved lens is increased, the focal length of the lens will:
Increase
As transducer diameter decreases, the beam spread:
Increases
skip
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At an interface between two different materials, an impedance difference results in:
Division of sound energy into transmitted and reflected modes
Attenuation is a difficult quantity to measure accurately, particularly in solid materials, at the test frequencies normally use The overall result usually observed includes other loss mechanisms which can include:
1. BEAM SPREAD
2. COUPLANT MISMATCH
3. TEST PIECE GEOMETRY
All of the above
Attenuation is a:
Test material parameter.
Beam divergence is a function of the dimensions of the crystal and the wavelength of the beam transmitted through a medium, and it:
increases if the frequency or crystal diameter is decrease
Compensation for the variation in echo height related to variations in discontinuity depth in the test material is known as:
Distance amplitude correction
Compression waves whose particle displacement is parallel to the direction of propagation are called:
Longitudinal waves
Delay-tip(stand-off)type contact search units are primarily used for:
Thickness measurement of flaw detection in thin materials.
During a straight beam ultrasonic test a discontinuity indication is detected which is small in amplitude compared to the loss in amplitude of back reflection. The orientation of this discontinuity is probably:
Such that complete loss of back reflection will result.
During straight beam testing, test specimens with non-parallel front and back surfaces can cause:
Partial or total loss of back reflection
During ultrasonic testing by the immersion method, it is frequently necessary to angulate the search unit when a discontinuity is located in order to:
Obtain a maximum response if the discontinuity is not originally oriented perpendicular to the ultrasonic beam.
Entry surface resolution is a characteristic of an ultrasonic testing system which defines its ability to:
Detect discontinuities located just beneath the entry surface in the part being teste
For aluminum and steel the longitudinal velocity is approximately ____________ the shear velocity:
Twice
For discontinuity geometries other than flat, the echo amplitude is usually from that observed for a flat defect, of similar orientation perpendicular to the sound beams.
Decreased
Gas discontinuities are reduced to flat discs or other shapes parallel to the surface by:
Rolling
Heat conduction, viscous friction, elastic hysteresis, and scattering are four different mechanisms which lead to:
attenuation
If a 5.0 MHz transducer is substituted for a 2.25 MHz transducer, what would be the effect on the wavelength of a longitudinal mode wave produced in the test specimen?
The wavelength would remain constant.
If the major dimensions of a discontinuity in a 6-inch thick aluminum plate lie parallel to the entry surface at a depth of 3 inches, it will be best detected by:
A straight beam test
If the velocity of a longitudinal mode wave in a given homogeneous material is .625 cm/micro se at 1/2 inch below the surface, what is the velocity at 2 inches below the surface?
The same as the velocity at 1/2 inch.
In a basic pulse-echo ultrasonic instrument, the component that coordinates the action and timing of other components is called a:
Synchronizer, clock, or timer.
In a basic pulse-echo ultrasonic instrument, the component that produces the voltage that activates the search unit is called:
Pulser
In a basic pulse-echo ultrasonic instrument, the component that produces visible signals on the CRT which are used to measure distance is called a:
Marker circuit
In a basic ultrasonic test pattern (A-scan) for contact testing, the initial pulse (assume no sweep delay is used):
IS THE HIGH INDICATION ON THE EXTREME LEFT SIDE OF THE SCREEN that represents the entry surface of the inspected part.
In a basic-pulse-echo ultrasonic instrument, the voltage producing component which activates the search unit is called:
Sweep circuit
In a B-scan display, the length of a screen indication from a discontinuity is related to:
The discontinuity’s length in the direction of the transducer travel.
In a liquid medium, the only mode of vibration that exists is:
Longitudinal
In a material with a given velocity, when frequency is increased, the wavelength will:
Decrease
In a test where the transducer is not perpendicular to the inspection surface, the angle of incidence is equal to:
The angle of reflection.
In addition to other functions, a probe manipulator in a mechanical immersion scanning unit permits:
Detection of obliquely-oriented discontinuities.
In an A-scan presentation, the horizontal base line represents the:
Elapsed time or distance
In an A-scan presentation, the horizontal line formed by the uniform and repeated movement of an electron beam across the fluorescent screen of a cathode ray tube is called:
A sweep line.
In an automatic scanning immersion unit, the bridge or carriage serves to:
Support the manipulator and scanner tube and to move it about transversely and longitudinally.
In an immersion inspection of raw material, the water travel distance should be:
Equal to the water travel distance used in setting up on the reference standards.
In an immersion test of a piece of steel or aluminum, the water distance appears on the display as a fairly wide space between the initial pulse and the front surface reflection because of:
Reduced velocity of sound in water as compared to test specimen.
In an ultrasonic instrument, the number of pulses produced by an instrument in a given period of time is known as the:
Pulse repetition rate.
In cases where the diameter of tubing being inspected is smaller than the diameter of the transducer, what can be used to confine the sound beam to the proper range of angles?
A collimator.
In contact testing, defects near the entry surface cannot always be detected because of:
The dead zone.
Another name for the dead zone is the near field or near-surface blind zone. This area is close to the transducer, where the initial pulse and its reflections can interfere with defect detection.
In contact testing, shear waves can be induced in the test material by:
Using a transducer mounted on a plastic wedge so that sound enters the part at an angle.
In contact testing, the entry surface indication is sometimes referred to as:
1. The initial pulse
2. The “main bang” or transmitter pulse
Both A and B
In general, discontinuities in wrought products tend to be oriented:
In the direction of grain flow.
In general, which waves will travel around gradual curves with little or no reflection from the curve?
Surface waves.
In immersion testing a wetting agent is added to the water to:
Help eliminate the formation of air bubbles.
In immersion testing in a small tank, a manually operated manipulator is used to:
Set the proper water path Set the proper transducer angle Both A and B
In immersion testing irrelevant or false indications caused by contoured surfaces are likely to result in a:
Broad-based indication.
In immersion testing, the accessory equipment to which the search cable and the search unit are attached is called a:
Search tube or scanning tube.
In immersion testing, the most commonly used couplant is:
Water
In immersion testing, the near field effects of a transducer may be eliminated by:
Using an appropriate water path.
In immersion testing, the position of the search unit is often varied to transmit sound into the test part at various angles to the front surface. Such a procedure is referred to as:
Angulation.
In immersion testing, verification that the search unit is normal to a flat entry surface is indicated by:
Maximum reflection from the entry surface
In inspecting a 4-inch diameter threaded steel cylinder for radial cracks extending from the root of the threads, it would be preferable to transmit:
Longitudinal waves from the end of the cylinder and perpendicular to the direction of the thread roots.
In steel, the velocity of sound is greatest in which of the following modes of vibration?
Longitudinal
In straight (normal) beam contact testing, a reduction in the back surface reflection amplitude could indicate:
Inadequate coupling. A flaw which is not normal to the beam. A near surface defect that cannot be resolved from the main bang (initial pulse). All of the above
In straight beam pulse echo testing a discontinuity with a rough reflecting surface perpendicular to the incident wave will have what effect on the detected signal in comparison to a smooth flat-bottom hole of the same size?
Decrease it.
In the basic pulse-echo instrument, the synchronizer, clock or timer circuit will determine the instrument’s:
pulse repetition rate
