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
