UT Test

Question 1

Echo of sound pressure striking transducer determines height of echo signal on display

Answer 1

amplitude

Question 2

Amplitude of displayed signal can be controlled with what?

Answer 2

Gain control

Question 3

Factors that impact velocity (3)

Answer 3

makeup of material, type of scan, temperature

Question 4

Max range of human hearing and min range of ultrasound waves

Answer 4

20000, >20000

Question 5

A reflection from an acoustic interface is what?

Answer 5

Echo

Question 6

What happens to sound as it travels through a non-homogenous material

Answer 6

It scatters

Question 7

What travels via displacement of molecules around a fixed point?

Answer 7

Sound wave

Question 8

What kind of sound waves require only elasticity and which waves require both elasticity and rigidity in the test object?

Answer 8

Just elasticity - longitudinal, both - Transverse(Shear), surface, plate.

Question 9

What type of wave has vibrations that are parallel to the direction of the wave?

Answer 9

Longitudnal

Question 10

What is the principle that says sound bends at the interface of two materials of different velocity?

Answer 10

Refraction. This is the concept behind shear waves.

Question 11

Crystal sources are made from which elements?

Answer 11

Barium and lead

Question 12

What data is displayed in the horizontal and vertical axis for A-Scan, B-Scan, C Scan

Answer 12

A Scan - horizontal = time, vertical = amplitude, B Scan is cross section of the object, S Scan is top view of object.

Question 13

Difference between Thickness gauge and Flaw Detector displays

Answer 13

Primary readout on thickness gauge is numerical followed by A Scan. Flaw detectors are the opposite.

Question 14

The ___ of echo sound pressure striking the transducer determines the height of the echo signal on the display.

Answer 14

amplitude

Question 15

Of what use is the detector?

Answer 15

provides various video modes for display of signals coming from the reciever?

Question 16

What are the benefits of narrow and broad-band display?

Answer 16

Narrow provides better test sensitivity, broad provides better resolution

Question 17

What control prevents undesirable low amplitude signals from being displayed?

Answer 17

Reject Control

Question 18

What probe should be used for examining parts with laminations before angle beam inspection

Answer 18

Twin crystal 0 probe

Question 19

What testing method should be used when testing for planar discontinuities?

Answer 19

Straight beam, dual crystal

Question 20

Indication on screen representing far boundary of test object

Answer 20

back wall echo

Question 21

Snell’s law describes?

Answer 21

relationship between velocity and the refracted angle

Question 22

Which probe is used to test for lack of sidewall fusion

Answer 22

angle probe

Question 23

What search unit would have the thinnest crystal? 25 mhz or 1 mhz

Answer 23

25 mhz

Question 24

probe used to test welds for toe cracks

Answer 24

angle probe

Question 25

Speed of a sound wave is ___?

Answer 25

consistent

Question 26

Mode conversion occurs when?

Answer 26

incident angle is not normal to the interface

Question 27

The second critical angle is the angle at the point of incidence at which?

Answer 27

surface waves are produced

Question 28

Which mode of vibration produces the shortest wavelength?

Answer 28

surface wave

Question 29

Which scrren view produces a plan type view of test object

Answer 29

C-Scan

Question 30

formula for wavelength

Answer 30

velocity/frequency

Question 31

frequncy marked on a transducer indicates what?

Answer 31

operating frequency

Question 32

greek letter for wavelength is?

Answer 32

l

Question 33

_ determines the relative amount of sound energy coupled through and reflected at an interface

Answer 33

acoustic impendance

Question 34

The amplitude on an A-Scan represents what?

Answer 34

amount of reflected energy coming back to the search unit

Question 35

What are the 3 casting processes?

Answer 35

Sand, investment, die

Question 36

Dead Zone is defined as?

Answer 36

distance covered by the front surface pulse width and recovery time.

Question 37

What kind of wave is produced at the second critical angle

Answer 37

surface wave

Question 38

Why isn't air a good transmitter of ultrasound

Answer 38

particle density is too low

Question 39

Atomic number is?

Answer 39

number of protons

Question 40

Is volumetric or planar defects considered most serious and why?

Answer 40

planar, because they are higher stress concentrators

Question 41

TIG equals

Answer 41

tungsten inert gas welding

Question 42

What type of wave is 3 wavelengths or less

Answer 42

lamb or plate

Question 43

What is Q factor

Answer 43

number of cycles for crystal vibrations to reach full amplitude

Question 44

initial pulse/dead zone is the area where__?

Answer 44

no reflection of the defect can be seen

Question 45

What is attenuation?

Answer 45

loss of energy in the far field due to composition of the test object

Question 46

what is the name of the angle when sound emerges from a second medium and the refracted angle is 90 degrees.

Answer 46

critical angle

Question 47

What is first critical angle

Answer 47

when long waves reach 90 degrees of refraction

Question 48

What happens to beam spread as frequency increases?

Answer 48

decreases

Question 49

What happens to beam spread as velocity decreases?

Answer 49

decreaes