General Dynamics Conair questions

Question 1

1-1

In recent years the use of quartz in ultrasonic transducers has been reduced because…

a) It is insoluble in most liquids and is very hard and water resistant
b) of the development of new and more efficient piezoelectric materials

Answer 1

b) of the development of new and more efficient piezoelectric materials

1-3

Question 2

1-3

An important advantage of using polarized ceramic transducers is that they…

a) operate well at a high voltage
b) are excellent generators of sound energy

Answer 2

b) are excellent generators of sound energy

1-5

Question 3

1-8

Transducer sensitivity is the ability of the transducer to detect small discontinuities?

Answer 3

True

1-10

Question 4

1-12

Which of the following statements are true?

a) Transducer sensitivity is rated by the amplitude of its response to a 2/64 inch flat bottomed hole
b The sensitivty of a transducer is rated by its ability to detect a flat bottomed hole at certain sizes at a specifc depth in a standard reference block

Answer 4

b The sensitivty of a transducer is rated by its ability to detect a flat bottomed hole at certain sizes at a specifc depth in a standard reference block

1-14

Question 5

1-16

Which of the following statements describes the resolution of the transducer?

a) a transducer capable of detecting a 3/64-inch-flat-bottomed-hole, four inches below the front surface of a standard reference block

b) A transducer capable of detecting a 5/64-inch-flat-bottomed hole, 1/8-inch below the surface of a standard reference block

Answer 5

b) A transducer capable of detecting a 5/64-inch-flat-bottomed hole, 1/8-inch below the surface of a standard reference block

1-18

Question 6

1-21

If the test results indicate that the sound energy is not reaching the back surface of the test specimen you would….

a) use a smaller transducer
b) use a larger transducer

Answer 6

b) use a larger transducer

1-23

Question 7

1-23

Large single-crystal transducers are limited to…

a) High frequency testing
b) Low frequency testing

Answer 7

b) Low frequency testing

1-25

Question 8

1-25

Which of the following is the better reason for testing a large, flat plate with a paint brush transducer?

a) its carefully matched crystals produce a sound beam of uniform sensitivity
b) it can scan large areas at high frequencies

Answer 8

b) it can scan large areas at high frequencies

1-27

Question 9

1-28

For greater sensitivity, which transducer frequency would you use?

a) 5 MHz
b) 10 MHz

Answer 9

b) 10 MHz

1-30

Question 10

1-30

The lower the frequency of the transducer, the deeper the sound penetration and the less the attenuation, but the greater the beam spread and the less the sensitivity?

Agree or disagree

Answer 10

Agree

1-32

Question 11

1-32

If testing conditions required the use of a 15 MHz transducer, would you use the contact testing method or the immersion testing method?

Answer 11

Immersion method

1-35

Question 12

1-40

Would you agree that the purpose of angle-beam transducers is also to generate shear waves?

Answer 12

Agree

1-42

Question 13

1-42

Can we also say that a surface wave transducer is an angle-beam transducer that generates a shear wave with a refracted angle of 90 degrees?

Agree

Disagree

Answer 13

Agree

1-44

Question 14

1-44

Devices added to the front of contact transducers to match the curvature of a test part are called…

a) curved shoes
b) contour correction lenses

Answer 14

a) curved shoes

1-46

Question 15

1-46

Which is the better statement?

a) all angle-beam transducers are identified by the refracted angle of the shear wave they produce in a given material

b) angle-beam transducers are identified in different ways by different manufacturers

Answer 15

b) angle-beam transducers are identified in different ways by different manufacturers

1-49

Question 16

1-50

Which is the correct statement?

a) Contour correction lenses are cylindrically focused lenses specially designed to improve the sensitivity of the test equipment

b) cylindrically-focused lenses that cause the sound energy from a transducer to strike curved test surfaces normal to the surface at all points are called contour correction lenses

Answer 16

a) Contour correction lenses are cylindrically focused lenses specially designed to improve the sensitivity of the test equipment

1-53

Question 17

1-53

Which is the correct statement?

a) Adding an acoustical lens to a transducer increases its sensitivity and resolution

b) Adding a spherically-focused lens to a transducer increases its usable range

Answer 17

a) Adding an acoustical lens to a transducer increases its sensitivity and resolution

1-54

Question 18

1-54

Which lens increases transducer sensitivity more?

a) spherically-focused lens

b) Cylindrically focused lens

Answer 18

a) spherically-focused lens

1-56

Question 19

1-59

When locating small discontinuities at the top of the surface in a part, which transducer would be best for locating them?

a) long focal length
b) short focal length

Answer 19

b) short focal length

1-61

Question 20

1-61

Choose the statement that best describes the function of a collimator

a) A collimator added to a transducer concentrates the sound beam into a straight path and increases the beam intensity

b) Collimators are added to transducers to reduce the beam spread and improve the directivity of the sound beam

Answer 20

b) Collimators are added to transducers to reduce the beam spread and improve the directivity of the sound beam

1-63

Question 21

1-65

Choose the correct statement

a) Wheel-type transducers are limited to through-transmission testing

b) Wheel-type transducers are used in through-transmission testing and pulse-echo testing

Answer 21

b) Wheel-type transducers are used in through-transmission testing and pulse-echo testing

1-67

Question 22

1-67

Do you agree or disagree with the following statement?

Single transducers are either transmitters only or receivers only and double transducers are one transmitter and one receiver?

Answer 22

Disagree

1-69

Question 23

1-69

Choose the correct statement

a) Double transducers have better surface resolution because the dead zone is shorter

b) double transducers have better surface resolution because they have more power

Answer 23

a) Double transducers have better surface resolution because the dead zone is shorter

1-70

Question 24

2-1

Which of the following is the reason for using a couplant between the transducer and the test surface in ultrasonic testing?

a) ultrasonic vibrations (sound energy) do not travel readily through air

b) A lubricant is required between the transducer and the test specimen to minimize crystal wear

Answer 24

a) ultrasonic vibrations (sound energy) do not travel readily through air

2-2

Question 25

2-2

Which is the correct statement?

a) The couplant must thoroughly wet the face of the transducer and the surface of the test specimen to ensure a good electrical ground

b) The couplant must thoroughly wet the face of the transducer and the surface of the test specmen to ensure good sonic coupling

Answer 25

b) The couplant must thoroughly wet the face of the transducer and the surface of the test specmen to ensure good sonic coupling

2-5

Question 26

2-5

Which do you think would be a better couplant in contact testing of metals..

a) water

b) oil

Answer 26

b) oil

2-7

Question 27

2-7

Which of the following is a determining factor for selecting a couplant?

a) size and frequency of the transducer

b) condition of the test surface

Answer 27

b) condition of the test surface

2-9

Question 28

2-9

Select the correct statement…

a) In contact testing, the couplant must be applied carefully to ensure good sound energy transfer into the test specimen

b) In contact testing, if the correct couplant is used, application is no problem provided plenty of couplant is used

Answer 28

a) In contact testing, the couplant must be applied carefully to ensure good sound energy transfer into the test specimen

2-10

Question 29

2-10

Select the correct statement…

a) The acoustic impedance of a couplant should be greater than the acoustic impedance of the test specimen

b) The acoustic impedance of a couplant should be between the acoustic impedance of the transducer and the acoustic impedance of the test specimen

Answer 29

b) The acoustic impedance of a couplant should be between the acoustic impedance of the transducer and the acoustic impedance of the test specimen

2-13

Question 30

3-4

Which of the following is correct?

a) Area amplitude blocks provide discontinuity size reference and distance amplitude blocks provide depth reference

b) Area amplitude blocks provide discontinuity depth reference and distance amplitude blocks provide size reference

Answer 30

a) Area amplitude blocks provide discontinuity size reference and distance amplitude blocks provide depth reference

3-5

Question 31

3-5

What diameter would a number 6 block have?

a) 6/64 inch diameter hole
b) 3/4 inch diameter hole

Answer 31

a) 6/64 inch diameter hole

3-7

Question 32

3-7

Area amplitude blocks can be used to verify the test systems linearity because…

a) the metal distances differ in the proportion to the hole size

b) the artificial discontinuities increase proportionately in size while the metal distance remains the same

Answer 32

b) the artificial discontinuities increase proportionately in size while the metal distance remains the same

3-10

Question 33

3-10

In a given set of distance amplitude blocks which is the known variable?

a) The flat-bottomed hole size
b) The metal distance

Answer 33

b) The metal distance

3-12

Question 34

3-13

If the pip on the CRT screen indicates a discontinuity 1-3/8 inches below the surface of the test specimen, which reference block would you compare it to?

a) reference block with 1-1/4 inches metal distance

b) Reference block with 1-3/4 inches metal distance

Answer 34

a) reference block with 1-1/4 inches metal distance

Question 35

3-14

When the amplitude of a pip from a discontinuity in a test specimen is the same as that from an artificial discontinuity in a reference block, and both are the same depth below the surface, is the discontinuity in the test specimen smaller than, the same size as, or larger than the artificial discontinuity?

a) smaller than

b) the same size as

c) larger than

Answer 35

c) Larger than

Question 36

3-18

Which is the more important advantage of the basic set of ASTM reference blocks?

a) The basic set of ASTM reference blocks provides both area amplitude and distance amplitude references in one set

b) The basic set of ASTM reference blocks covers a wide range of conditions with fewer blocks

Answer 36

a) The basic set of ASTM reference blocks provides both area amplitude and distance amplitude references in one set

Question 37

3-19

When choosing a standard reference block with which to evaluate the sound energy responses from a test specimen…

a) the material of the reference block is not important as long as the metal distance of the reference block is the same as, or close to, the depth of the discontinuity in the test part

b) the material of the reference block must be the same as, or similar to, that of the test part

Answer 37

b) the material of the reference block must be the same as, or similar to, that of the test part

Question 38

3-22

In ultrasonic testing all discontinuity indications are evaluated by comparing them to…

a) standard reference blocks such as the Alcoa series A and B blocks and the ASTM reference blocks

b) standard reference blocks or to specifically prepared representative samples

Answer 38

b) standard reference blocks or to specifically prepared representative samples

Question 39

3-25

Which of the following statements describes the purpose of the IIW calibraion block?

a) The purpose of the IIW calibration block is to provide a direct relationship between the artificial discontinuities in the block and true discontinuities in a test specimen

b) The IIW calibration block is used to check certain operational characteristics of ultrasonic instruments and transducers and to aid in making certain adjustments

Answer 39

b) The IIW calibration block is used to check certain operational characteristics of ultrasonic instruments and transducers and to aid in making certain adjustments

Question 40

3-31

If the instrument/transducer combination cannot seperate the pips satisfactorily you would…

a) try a different transducer

b) use a reference block of different material

Answer 40

a) try a different transducer