General dynamics Conair questions book 2 Flashcards
1-2
Select the statement below which most nearly describes the nature of the sound introduced nto the material?
a) Short pulses of ultrasonic energy
b) continuous ultrasonic energy
a) Short pulses of ultrasonic energy
1-4
**Select the best completion for the following statement
Through-transmission ultrasonic testing….**
a) always uses seperate transmitting and receiving transducers
b) receives sound reflections on the transmitting trandsucer
a) always uses seperate transmitting and receiving transducers
1-5
In contact testing using the pulse-echo system, three things are required: 1) a test instrument, 2) a suitable couplant, 3) a test specimen.
In this case, the transducer is brought into contact with the test specimen with the couplant between the transducer and the specimen.
**
Which is the best completion for the following statement?**
Contact testing means that….
a) transducer is placed directly in contact with the test specimen
b) transducer is coupled through a thin layer of couplant to the test specimen
1-9
There are many advantages to the immersion method as compared to contact testing. For the moment though, the important difference to remember is that both the transducer and the test specimen are immersed in couplant.
In terms of immersion testing, is it necessaryto add oil to the tank?
A) yes
b) no
b) no
1-13
Given two pulse-echo instruments. Instrument one is capable of clearly showing the difference in reflections from discontinuities that are 1/4 inch apart in depth while instrument two can only distinguish a difference in reflections from discontinuities that are 1/2 inch apart in depth.
Instrument number one then can be said to have the best…
a) sensitivity
b) resolution
b) resolution
1-16
Which of the following systems would you select to test a specimen if you needed to know the depth and size of any discontinuity found?
a) through-transmission
b) Pulse-echo
b) Pulse-echo
1-19
What is one of the greatest disadvantages of contact testing?
a) lack of near-surface resolution
b) difficulty in maintaining uniform acoustical coupling
b) difficulty in maintaining uniform acoustical coupling
1-23
Does the immersion method lend itself to automatic scanning and recording?
a) yes
b) no
A) yes
1-24
Suppose we had a specimen at some field location that we anted to test ultrasonically. which method would you most likely use?
a) contact method
b) immersion method
a) contact method
1-26
Among the variables controlled by the ultrasonic operator are…
a) equipment selection and operation
b) test specimen and transducer to be used
a) equipment selection and operation
1-28
Given a particular test specimen, which of the following may be modified by the operator?
a) shape of the specimen
b) adjustment of the test instrument
b) adjustment of the test instrument
1-33
It appears that a good test procedure and its acceptance standard provides a lot of detail about an ultrasonic test to be performed. would you say that this test documentation reduced the need for operator training, or has no effect on the need for training?
a) reduces need for operator training
b) has no effect on operator training requirements
b) has no effect on operator training requirements
1-35
Calibration or standardization of ultrasonic instruments is based on reflections from?
a) the opposite surface of a test block of known precise dimension
b) precisely machined holes in test blocks providing an air interface
b) precisely machined holes in test blocks providing an air interface
1-37
Is the following statement true or false?
Test blocks made from extruded aluminium bar stock would be suitable for standardizing the test instrument prior to performing tests on aluminium castings
a) True
b) False
b) False
1-39
Is the following statement true or false?
A discontinuity from a test specimen that is equal in height to an indication from a test block indicates the discontinuity is actually larger than the flat bottomed hole?
a) true
b) false
a) true
2-2
When using through-transmission, are discontinuity indications directly proportional to the amount of sound energy reflected by the discontinuity?
a) Yes
b) No
b) no
2-4
In through-transmission testing, the receiving transducer does not “see” the reflection from the front surface of the test specimen. At what minimum depth in the test specimen do you think the presence of discontinuities can be detected?
a) a thousandths of an inch
b) about 1/4 inch
a) a thousandths of an inch
2-7
Select the best completing for the following statement
Ultrasonic equipment selection is dependant on..
a) Test specimen characteristics only
b) The test situation
b) The test situation
2-9
a coarse-grained internal structure in a test specimen will require the selection of a…
a) high test frequency
b) low test frequency
b) low test frequency
2-11
Which material has the finer grain structure, an aluminium casting or aluminium plate?
a) Aluminium casting
b) Aluminium plate
b) Aluminium plate
2-13
Frequency is one of the factors that determines the ability of a testing system to detect discontinuities c;lose to the surface. which of the following will afford the best ‘near surface’ discontinuity detection?
a) low test frequencies
b) High test frequencies
b) High test frequencies
2-16
At a given ultrasonic test frequency which will give the largest beam spread?
a) a large transducer
b) a small transducer
b) a small transducer
2-18
Suppose you are testing a specimen that is over 10 feet in length. A discontinuity is suspected to lie 10 feet from the test surface. You have selected 2.25 Hz as the frequency most likely to give the best test results. With a choice of a 1/2 inch or a 1 inch diameter transducer, which should be selected to penetrate to and beyond the susoected discontinuity?
a) 1/2 inch transducer
b) 1-inch transducer
b) 1-inch transducer
2-20
If an angle beam transducer will produce a beam angle of 45 degrees in steel and you are to use this transducer for testing aluminium, will the angle of the sound beam in aluminium be greater or less than 45 degre? assume that the velocity of sound in aluminium is less than the velocity in steel.
a) less than 45 degree
b) more than 45 degree
a) less than 45 degree
2-23
Suppose you are conducting a test on a vertical surface. Which would be the most suitable couplant?
a) oil
b) water with wetting agent
a) oil
2-26
Is the following statement true or false?
A couplant will not be required when making the above check for test instrument operating efficiency since the test blocks are very precisely machined and the test surface smooth enough that good contact will be made between the transducer and test surface
a) true
b) false
b) false
2-33
Suppose that the rear surface of a test specimen lies at an angle of 20 degree to the front surface. What will be the effect on a normal A-scan display considering that the basic elements of the display always include front and back surface indications under normal conditions?
a) no effect
b) loss of back surface reflection
b) loss of back surface reflection
2-29
Should the test instrument be adjusted for a long or a short pulse when testing a thick specimen with a suspected discontinuity about 10 inches below the surface?
a) long pulse
b) short pulse
a) long pulse
2-33
The angle of incidence of the sound beam at the surface of the test specimen is determined by the fixed angle of the lucite wedge. Which of the following characteristics determines the angle of the sound beam in the test specimen?
a) acoustic impedance
b) velocity of sound
b) velocity of sound
2-43
Suppose you are testing a specimen with a test surface having a 90 degree angle. What effect will the angle have on the surface wave?
a) no effect
b) reflecion of sound wave
b) reflecion of sound wave
2-47
Is the following statement true or false? The propagation of plate (lamb) waves is not depndent on the material properties of the test specimen?
A) true
B) false
B) false
2-51
Would you say a two-transducer pulse-echo system is more sensitive to the detection of all discontinuities than a single-transducer system?
a) yes
b) no
b) no
3-1
If you have a choice between a 1.0- and 2.25 megahertz transducer for testing a casting, which would be the most practical to select?
a) 2.25 MHz
b) 1.0 MHz
b) 1.0 MHz
3-11
Will an end to end of a 10-foot bar that results in a large back-surface reflection and no large discontinuity indications mean the bar has no discontinuities?
a) no
b) yes
a) no
3-9
If a 100% test is to be made of a sheet of steel 5 feet by 5 feet, would it be more practical to select a straight or angle beam technique?
a) straight beam
b) angle beam
b) angle beam
3-11
Should an ultrasonic test of a plate by angle-beam techniques be attempted with no knowledge of the general acceptability of the plate, or should some method of gross checking for discontinuities be accomplished first?
a) angle-beam test
b) gross check
b) gross check
3-13
How are discontinuities in rolled plate likely to be oriented?
a) paralell to the surface
b) at an angle to the surface
a) parralell to the surface
3-14
Assume you are testing a plate in accordance with an ultrasonic accetpance standard. Would you normally expect the reference notch dimensions to be prescribed by the standard?
a) no
b) yes
b) yes
3-17
If you recieve a stronger signal at one angle than another, does this mean an error was made during scanning?
a) yes
b) no
b) no
3-19
Assume you have the task of testing a rolled plate for surface defects. How many surfaces should you have access to?
a) one
b) two
b) two
3-21
Suppose you do not have a variable-angle transducer available. you do not have several fixed-angle transducers at various frequencies. do you think it will be possible to generate plate waves in a test plate?
a) yes
b) no
a) yes
3-23
What type of transducer would you select to conduct an ultrasonic test on a section of pipe with an outside diameter of 6 inches?
a) curved shoe, straight beam
b) curved shoe, angle beam
b) curved shoe, angle beam
3-27
If you are selecting a material for the construction of a contact shoe for use in testing a pipe, which of the following materials will you select?
a) same as pipe
b) same as angle wedge
b) same as the angle wedge
3-30
Assume that a shear wave is being transmitted into a pipe in a clockwise direction. A discontinuity exists at a 220 degree around the circumference from the point of entry of the sound beam. Will this discontinuity indication appear to the left or the right of the revolution indication?
a) left
b) right
b) right
3-33
Is the following statement true or false? the inner and outer reference notches in a sample piece of pipe should be cut at the same location on the circumference of the pipe?
a) true
b) false
b) false
3-42
When testing a weld do you think you will receive any reflections from the weld area even if there are no discontinuities present?
a) no
b) yes
b) yes
3-45
A reflection will be received from a discontinuity in the weld even when the center of the beam does not strike it. the maximum reflection, however, will be received when the discontinuity is struck by the center of the beam.
a) false
b) true
b) true
3-48
Skip distance is a function of which of the following factors?
a) Frequency
b) Wedge angle
b) Wedge angle
3-51
Will skip distance increase or decrease as thickness of the test specimen is increased, assuming the same wedge is used and the same material properties are maintained?
a) Decrease
b) increase
b) increase
3-53
Judgement must be used in selecting a large angle of incidence for the generation of shear waves. What will happen if the angle selected is so large that the angle of refraction is 90 degrees?
a) skip distance is too great
b) surface waves are produced
b) surface waves are produced
3-55
Is the following statement true or false?
As sheet thickness is increased, beam angle should be increased?
a) true
b) false
b) false
3-63
A weld testing rules that is designed for locating discontinuities in a weld in a 1/2-inch steel plate should not be used to locate discontinuities in a weld in a 1/2-inch aluminium plate. which of the following reasons would explain this?
a) different reflection angles
b) different refraction angles
b) different refraction angles
3-75
If you are determining the magnitude of the reflection that will be received from the hole in the reference standard, at what distance should the transducer be placed from the hole?
a) minimum and maximum for weld scanning
b) mid-point of area of scan
a) minimum and maximum for weld scanning
4-2
water used in test tanls as a couplant usually requires the addition of a wetting agent. The wetting agent serves the purpose of…
a) elimination of air bubbles
b) aerating the water
a) elimination of air bubbles
4-3
Which of the following items should you adjust if you want to determine the extent of the area of a large discontinuity?
a) manipulator
b) manual positioner
b) manual positioner
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