UT chapter 4

Question 1

Name 3 types of transducers in use between the 1930’s-1980’s

Answer 1

Polarized Ceramic
barium titanate
lithium sulfate

Question 2

Name 3 types of transducers in use today.

Answer 2

barium titanate
lead metaniobate
lead zinconate titanate

Question 3

a technician may choose a given frequency transducer based on the__________ that project specifications require.

Answer 3

Sensitivity

Question 4

Most ultrasonic testing is performed between____ and______.

Answer 4

.2, 25MHz

Question 5

The thiner the crystal, the_____ the frequency

Answer 5

Higher

Question 6

The near field is composed of localized_____ and _____ beam intensities.

Answer 6

High, Low

Question 7

the length of the near field can be shortened by_____ the frequency.

Answer 7

lowering

Question 8

The smaller the crystal, the_____ the beam spread

Answer 8

Greater

Question 9

As frequency is______ and as transducer diameter is______, beam spread is_______

Answer 9

Increased, Increased, decreased

Question 10

Paintbrush transducers provide a long, narrow, rectangular beam for scanning_______ surfaces

Answer 10

large

Question 11

Dual element transducers utilize______ elements of crystals

Answer 11

3

Question 12

in the dual element transducer, one crystal _______ and the other crystal ______ the returning sound

Answer 12

transmitter, receiver

Question 13

What does the term “Longitudinal” mean?

Answer 13

the sound of energy from the transducer is transmitted into the test object in a direction perpendicular to the test surface.

Question 14

Shear wave transducers direct the sound beam into the test surface at an ______ that is not _______

Answer 14

angle, perpendicular

Question 15

what is the purpose of a plastic shoe?

Answer 15

to propagate shear, surface or plate waves into the test object by mode conversion.