UT Level 2 Flashcards by Kayla Silver

For high temperature measurements the preferred piezoelectric material is:

a) quartz
b) lithium sulphate hydrate
c) lithium niobate
d) PZT

quartz

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If used, shear waves generated by a Y-cut crystal are coupled to a soild by:

a) solid adhesives
b)non-Newtonian viscous liquids (like bees wax)
c)high pressure dry contact
d) all of the above

all of the above

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When a group of UT elements are arranged in straight line and operated sequentially, usually to build up a B-scan image, such a probe is called a:

a) sequenced array
b) linear array
c) phaser
d) both a and b

d) both a and b

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Polarization of PZT crystals is accomplished using:

a) strong permanent magnets
b) no applied electric current but exposure to heat
c) strong alternating voltage/current
d) strong direct voltage/current

strong direct voltage/current

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To a degree, the mechanical deformation of a piezoelectric material is directly proportional to the:

a) acoustic impedance of the piezo material
b) the amount of pressure you exert onto your probe when coupled to object
c) acoustic impedance of the backing material
d) applied voltage

applied voltage

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Most piezoelectric ceramics (ferroelectrics) are:

a) also ferromagnetic
b) statically charged
c) are better receivers than transmitters
d) polycrystalline

polycrystalline

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When required to determine pulse length it will be given as:

a) a specified number of microseconds
b) a distance in mm in the material
c) pulse length is never a consideration
d) either a or b may be required

d) either a or b may be required

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When using quartz as a piezoelectric transducer, longitudinal waves are generated from the _____ crystal.

a) GT-cut
b) Z-cut
c) Y-cut
d) X-cut

X-cut

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Resolving power (resolution) of broadband transducers:

a) increases with sound path distance
b) decreases with sound path distance
c) is independent of sound path distance
d) depends solely on near field length

depends solely on near field length

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When ferro-electric ceramics such as PZT are heated above their curie point and held under a bias voltage while cooling to 80 deg C they are considered:

a) neutralized
b) annealed
c) poled or polarized
d) charged

poled or polarized

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When dealing with ultrasonic transducers the letters PZT stand for:

a) Paul Zamfir Tait, the discoverer of piezo-ceramics
b) lead zirconate titanate
c) phosphoric zirconate tungstenate
d) none of the answers provided

lead zirconate titanate

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The purpose of the backing material is to:

a) provide mechanical support
b) absorb backward moving sound waves
c) provide damping to reduce ringing
d) all of the above

d) all of the above

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A significant disadvantage of PZT as a transducer material is its:

a) low density
b) exceptionally high electromechanical coupling coefficient
c) high curie point
d) high acoustic impedance preventing good matching

high acoustic impedance preventing good matching

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Which of the following is not a consideration when selecting probe frequency?

a) sound path distance
b) defect orientation
c) grain structure of the test material
d) probe dimensions

defect orientation

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Pulse length determines a probes’:

a) frequency
b) depth resolution
c) damping
d) acoustic impedance

depth resolution

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A disadvantage of a narrowband receiver in UT instruments is:

a) non-logarithmic amplification ability
b) RF display is not available
c) pulses are broadened reducing resolution
d) many frequencies genetrated

pulses are broadened reducing resolution

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When analyzing a probe to determine its dominant frequency you find it gives 4.4 cycles in 2 microseconds when displayed on an unrectified trace. The dominant frequency is therefore:

a) 9.6 Mhz
b) 2.2 KHz
c) 2.2 Mhz
d) 4.4 MHz

2.2 Mhz

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The display of remnant reflections originating from previously transmitted pulses due to too high a PRF are called:

a) transients
b) none of the answers
c) ghost echoes
d) trip signals

ghost echoes

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Transmitter voltage pulse is triggered by the:
a) probe resonance
b) triggered by the transducer
c) control pulse of the sweep generator
d) sweep delay control

control pulse of the sweep generator

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To determine the dominant frequency of a probe you would require:

a) a rectified signal on a baseline calibrated in distance
b) a reference probe
c) an unrectified signal on a baseline calibrated in time
d) an impedance matching circuit

an unrectified signal on a baseline calibrated in time

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Rayleigh waves can be used in steel to penetrate up to:

a) 10 cm
b) 10 mm
c) 1 m
d) 1 wavelength

1 wavelength

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As frequency increases in ultrasonic testing, the angle of beam divergence of a given crystal diameter

a) increases
b) decreases
c) varies uniformly through each wavelength
d) remains unchanged

decreases

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Which of the following is a reference reflector that is not dependent on beam angle?

a) a side drilled hole parallel to plate surface
b) a vee notch
c) a flat bottom hole FBH
d) a disc shaped laminar reflector

a side drilled hole parallel to plate surface

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Given a 10MHz probe vibrating into water, with a velocity of 1500m/s, what is the wavelength of the longitudinal wave?

a) 0.6 cm
b) 1.5 mm
c) 0.15 mm
d) 1.5 cm

0.15 mm

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On an A-scan display, what represents the intensity of a reflected beam? a) signal amplitude b) horizontal screen location c) signal brightness d) echo pulse width

signal amplitude

In transverse waves, the particle motion is: a) in counterclockwise ellipses b) retrograde c) right angles to the direction of wave propagation d) parallel to the direction of wave propagation

right angles to the direction of wave propagation

The limiting factor (out of the available selections) for how short a wavelength may exist in an elastic wave is: a) the frequency content of the pulses b) the acoustic or molecular spacing of the material c) the PRF d) sound velocity of material

sound velocity of material

Mechanical wave motion requires: a) particle motion b) low pressure c) ionic bonding and disbonding d) high pressure

particle motion

The angle of divergence is a function of: a) crystal thickness of the probe b) crystal shape and velocity of sound in material c) crystal dimension (diameter) d) all of the answers

all of the answers

Sizing of defects located in the near zone is difficult because of: a) uncertainties of sound pressure at right angles to the beam axis b) uncertainties of sound pressure along the beam axis c) frequency variations d) both inconsistency/uncertainty of sound pressure and frequency variations in the beam

uncertainties of sound pressure along the beam axis

The repeated reflections of ultrasonic pulses from between surfaces or discontinuities within a body are called: a) ghost echoes b) wrap-around c) multiple echoes d) sing-around

multiple echoes

The zero time on a contact normal beam probe: a) is determined indirectly by calibration blocks b) corresponds to the rising edge of the main bang c) corresponds to the falling edge of the main bang

corresponds to the rising edge of the main bang

The angle of divergence is: a) decreases with increasing wavelength b) applicable to the far zone only c) increases with increasing probe dimensions d) constant for a given piezoelectric material

applicable to the far zone only

To avoid interfering ghost echoes when UT testing is done on very thin specimens the operator must: a) reduce the PRF b) turn off any nearby fluorescent lights c) increase the PRF d) decrease the receiver frequency band

reduce the PRF

Lamb waves are used in testing: a) bolts b) composite materials c) liquids d) thin bar or plate

thin bar or plate

The wavelength of an ultrasonic wave is; a) directly proportional to velocity and frequency b) inversely proportional to velocity and directly proportional to frequency c) directly proportional to velocity and inversely proportional to frequency d) equal to the product of velocity and frequency

directly proportional to velocity and inversely proportional to frequency

On an A-scan display, the dead zone refers to: a) the distance contained within the near field b) the area outside the beam spread c) the area between the near field and the far field d) the distance covered by the front surface pulse width and recovery time

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

The only significant sound wave mode that travels through a liquid is: a) shear wave b) rayleigh wave c) surface wave d) longitudinal wave

longitudinal wave

As temperature of a solid increases the attenuation of sound in that object tends to: a) decrease b) increase c) vary sinusoidally d) remain constant

increase

Given a cube of iron (long velocity is 5800 m/s), pulse-echo multiples are seen every 100 microseconds. What is the thickness of the iron? a) 29 cm b) 100 mm C) 29 mm d) 58 cm

29 cm

The amount of time between two compressions and two rarefactions of an elastic wave is called (Hint: think of our content on wavelength, frequency and time related to cycle): a) velocity b) frequency c) period d) wavelength

period

The length of the zone adjacent to a transducer in which fluctuations in sound pressure occur is mostly affected by: a) the diameter of the transducer b) frequency of the transducer c) the length of the transducer cable d) both a and b

d) both a and b

Because most liquids do not possess this quality they do not support transverse waves: a) inertia b) density c) shear strength d) plastic phase

shear strength

The differences in signals received from identical reflectors at different material distances from a transducer may be caused by: a) near field effects b) beam divergence c) material attenuation d) all of the above

all of the above

The difference between a compression and shear wave is: a) particle direction/motion b) qualitative measure c) quantitative measure d) amplitude

particle direction/motion

From our understanding of UT instrument settings in Pulse echo mode using a transducer that transmits and receives sound, when testing thick specimens, it may be advisable to?: a) change to a higher frequency b) decrease the pulse repetition frequency c) add reject or suppression to the trace d) use a delay line

decrease the pulse repetition frequency

Which of the following would be considered application(s) of ultrasonic techniques? a) determination of a material's elastic modulus b) study of a materials metallurgical structure c) measurement of a material's thickness d) all of the above

d) all of the above

In straight (normal) beam contact testing, a reduction in the back surface reflection amplitude could indicate; a) a flaw which is not normal to the beam b) inadequate coupling c) a near surface defect that cannot be resolved from the main bang d) all of the above

d) all of the above

If a signal is reduced from 84% to 42% FSH, the number of dB gain removed from the receiver is: a) 6 b) 42 c) 12 d) 2

The gain or attenuation setting at which indications are assessed is the ________ level: a) maximized b) scanning c) reference d) threshold

reference

Instrument settings which relate a reference echo of reproducible amplitude with which other instrument settings relating to a discontinuity echo are compared is the: a) reference sensitivity b) scanning level c) overall system gain d) threshold level

reference sensitivity

If 3 dB gain was removed from a 100%FSH signal the resulting signal would be _______%FSH: a) 85 b) 71 c) 94 d) 97

If a signal is dropped from 100%FSH to 32%FSH the number of dB gain removed from the receiver is: a) 10 b) 6 c) 14 d) 4

In Snell's law, there will be no first critical angle if the: a) incorrect, there will always be a first critical angle b) acoustic impedance of the refracting medium is greater than 1 c) acoustic velocity in the refracting medium is less than in the incident medium d) incident angle does not exceed 89 deg

acoustic velocity in the refracting medium is less than in the incident medium

The ratio of the incident sound pressure to the reflected sound pressure is called the a) coefficient of transmission b) acoustic intensity c) acoustic impedance d) coefficient of reflection

coefficient of reflection

The critical angle occurs when the sine of the refracted angle equals a) 1.414 b) 0.846 c) 0.707 d) 1.00

1.00

Snell's Law can be applied to reflected waves: a) always b) not needed c) only if temperature differences are allowed for d) for normal incidence only

not needed

In determining the coefficient of reflection, a negative value indicates a) loss of sound pressure b) reduced amplitude c) phase reversal relative to the incident wave d) none of the options

phase reversal relative to the incident wave

Maximum acoustic energy is coupled from one medium to another when the acoustic impedance of the first medium is _________ the second a) the same as b) less than c) twice the value of d) greater than

the same as

Incidence of a sound wave from a solid to a gas is considered a free boundary condition because: a) the acoustic impedance of a gas is essentially zero b) none of the options c) there are no particles in a gas d) all sound is lost in transmission

the acoustic impedance of a gas is essentially zero

When is the coefficient of transmission a negative value a) if Z incident is greater than Z transmitted b) if Z incident is less than Z transmitted c) never d) if Z incident equals Z transmitted

never

At a solid to free boundary interface, an obliquely incident longitudinal wave from the solid can result in, at most: a) a reflected longitudinal and reflected shear wave b) a reflected longitudinal wave only c) a refracted longitudinal long wave d) a reflected longitudinal and reflected shear and refracted longitudinal wave.

a reflected longitudinal and reflected shear wave

Given Z water is 1.5 and Z steel is 45, the coefficient of transmission of a normally incident wave from water is: a) -3.000 b) -0.065 c) 0.065 d) 1.935

0.065

The angle of incidence from Lucite, Vlong is 2760 m/s to produce a 60 deg refracted shear in steel, Vshear is 3240 m/s Vlong is 5900 m/s is: a) 48.3 deg b) 34.6 deg c) 23.1 deg d) 58,1 deg

34.6 deg

For a given ultrasonic beam impinging on a surface, the angle of incidence, the angle of reflection and the normal to that surface are: a) incident angle b) refracted angle c) longitudinal waves angle d) reflected shear wave

in the same plane

The critical angle refers to: a) incident angle b) refracted angle c) longitudinal waves angle d) reflected shear wave

incident angle

For a shear wave travelling from steel to water incident on the boundary at 10 deg will give a refracted shear wave in water with the angle of a) 20 deg b) 5 deg c) 0 deg d) none of the angle options provided

d) none of the angle options provided

Loss of acoustic energy in a material due to scatter, absorption and dispersion is called: a) suppression b) damping c) attenuation

attenuation

Scatter attributed to grain structure can be neglected for grain sizes below at least _______ wavelength a) 1 b) 1/1000 c) 1/100 d) 1/10

1/100

When constructing a DAC (Distance Amplitude Correction) curve the reference sensivity is established by: a) grass level b) the 1/4 t SDH c) the 1/2 t SDH d) the SDH stipulated in the procedure or standing instruction document

the SDH stipulated in the procedure or standing instruction document

For a plane wave, sound pressure is reduced by attenuation in a _______ fashion a) random b) exponential c) linear d) none of the options

exponential

The primary method of determining beam angle is by use of: a) the Rompas block b) the centre of beam line on the SANDT diagram c) the IIW block d) trigonometry

the IIW block

When examining materials for planar flaws close to the surface oriented parallel to the part surface, what testing method and probe design is best used: a) through transmission b) normal beam single crystal c) dual crystal normal beam d) angle beam

dual crystal normal beam

Range settings for longitudinal inspections are to have a minimum soundpath of _______T where T is the thickness of the test material a) 2.5 b) 2 c) 1.5 d) 1

Ratios of ultrasonic sound intensity are given in decibels (dB). They are calculated from the equation where J1 and J2 are acoustic intensities: a) 20 log(J1/J2) b) 20 Ln(J1/J2) c) 10 log(J1/J2) d) 10 Ln(J1/J2)

20 log(J1/J2)

When checking the BIP of an angle beam probe, the probe is unacceptable if it exceeds the BIP inscribed on the probe by the manufacturer by (best answer): a) +/- 1 deg b) +/- 1 mm c) +/- 2 deg d) +/- 0,5 mm

+/- 1 mm

Analysis of the frequency content of signals returned from flaws is called: a) emission counting b) ultrasonic spectroscopy c) fast fourier transform (FFT) d) b-scanning

fast fourier transform (FFT)

In an ultrasonic instrument, the number of pulses produced in a given period of time is known as: a) frequency b) pulse repetition rate c) pulse length of the instrument d) pulse recovery time

pulse repetition rate

The ultrasonic testing technique in which finger damping is most effective in locating a discontinuity is the; a) surface wave technique b) longitudinal wave technique c) compressional wave technique d) shear wave technique

surface wave technique

The method whereby a discontinuity is detected and evaluated using reflected pulses: a) through transmission method b) crack tip diffraction c) pulse-echo method d) bulk wave testing

pulse-echo method

A probe which contains separate transmit and receive crystals in the same housing is called: a) delta probe b) normal probe c) T-R probe d) dual crystal probe

dual crystal probe

Maximum acoustic energy is coupled from one medium to another when the acoustic impedance of the first medium is _________ the second a) greater than b) the same as c) twice the value of d) less than

the same as

The process of adjusting an instrument or device to a reference standard is referred to as: a) angulation b) calibration c) correcting for distance amplitude variations d) scanning

calibration

When using a transmit transducer and a receive transducer together at the same time, the configuration may be: a) tandem b) pitch-catch c) through transmission d) all of the above

all of the above

A discontinuity whose angle, size and location or properties make it detrimental to the useful service of the product in which it occurs or which exceeds the accept/reject criteria is a/n a) defect b) flaw c) slag inclusion d) crack

defect

In general shear waves are more sensitive to small discontinuities than longitudinal waves for a given frequency and in a given material because; a) the wavelength of shear waves is shorter than the wavelength of longitudinal waves b) shear waves are not as easily dispersed in the material c) the direction of particle motion for the shear wave is more sensitive to discontinuities d) the wavelength of shear waves is longer than the wavelength of longitudinal waves

the wavelength of shear waves is shorter than the wavelength of longitudinal waves

Information obtained about the exit point and refracted angle of an angle beam probe: a) is fixed by the manufacturer b) is qualitative only c) none of the options d) must be checked periodically since the probe is subject to wear

must be checked periodically since the probe is subject to wear

The effect of absorption can be to some extent be reduced by: a) increasing transmitter voltage b) increasing receiver voltage c) decreasing frequency d) all of the above

all of the above

A curve showing the relationship of amplitude to distance travelled to reflectors of the same area is usually referred to as a(an): a) AVG curve b)DAC curve c)NDT curve dDGS curve

DAC curve

A "normal" probe is one which: a) operates at half wave resonance b) operates at quarter wave resonance c) introduces sound into a test piece at right angles to the test surface d) has tungsten powder imbedded in its backing energy

introduces sound into a test piece at right angles to the test surface

The velocity of sound is : a) varies inversely with wavelength b) constant for all materials c) is characteristic of a material d) varies with frequency

is characteristic of a material

When testing a thin specimen it may be desirable to: a) decrease pulse energy b) decrease pulse length c) increase PRF d) all of the above

all of the above

A narrow high intensity ultrasound beam capable of finding very small flaws has its disadvantage in: a) characterizing the flaw b) requiring a small scanning grid (small coverage area) c) sizing the flaw d) none of the answers provided

requiring a small scanning grid (small coverage area)

The acoustic impedance of a material is used to determine the: a) beam spread within the material b) attenuation within the material c) angle of refraction at an interface d) relative amounts of sound energy coupled through and reflected at an interface

relative amounts of sound energy coupled through and reflected at an interface

The gain setting at which indications are assessed is the ________ level: a) be;; b) threshold c) reference d) scan

reference

A primary purpose of a reference standard is: a) to give the technician a tool for determining exact discontinuity size b) to provide assurance that all discontinuities smaller than a certain specified reference reflector are capable of being detected by the test c) to provide a guide for adjusting instrument controls to reveal discontinuities that are considered harmful to the end use of a product d) to provide a standard reflector which simulates natural discontinuities of a critical size

to provide a standard reflector which simulates natural discontinuities of a critical size

In ultrasonic testing, the actual point of focusing of sound is not possible due to: a) damping effects b) diffraction effects c) asymmetric vibrations d) divergence in the far zone

divergence in the far zone