test prep Flashcards
Ultrasonic testing is used for___examination of materials.
Volumetric
____ can be credited with early research and development in UT testing.
Dr.F. Firestone
This early research was conducted during the ____
1940’s
____ sounds an UT have similar characteristic.
Audible
One characteristic of UT is?
High Frecuency
UT is a form of ____ energy.
Vibration
UT Examination can be successfully performed on plastic material.
true or false
True
Material Thickness can be measured using UT. TRUE OR FALSE
TRUE
___ Properties of material can be correlated to the mechanical properties of that material.
Acoustical
The reliability of UT examination is dependent on the ____.
Operator
UT is high frequency sound between 20,000 and 25,000 cycle per minutes.
true or false
True
Sound is a form _____ energy.
Vibration
The device use to generate UT is called a _____.
Transducer
One cycle per second is the same as one Hertz. true or false
True
Transducer are made from ______ materials.
Piezoelectric
what is the Crystal or Piezoelectric element capable of doing?
The Crystal is capable of changing electrical energy to mechanical energy and mechanical energy to electric energy.
When performing an UT inspection using Pulse-Echo technique, access to only one side. true or false?
True
To perform a through transmission UT inspection, at least two transducer should be used. true or false
True
The distance a wave advances while completing a cycle is called a ____.
Wavelength
The symbol used to represent wave length is the _____ lambda.
Greek letter
In UT inspection, the major variable used to control wavelength is ______.
Frequency
The velocity of a Longitudinal in Aluminum is 245,000 inch per second. with a 1 MHZ transducer. what’s the wavelength?
.25 inches
Decreasing wavelength in UT test decreases sensitivity. true or false
TRUE
Loss of sound energy as a sound beam travels through a material is referred to as ____.
Attenuation
Discontinuities can be detected by UT inspection because some UT will be _____.
Reflected
Acoustic impedance value for different material are dependent on sound velocity and material _____ variations.
Density
Acoustic impedance differences at boundaries between different material determines how much sound will pass through the boundary. true or false
True
The distance from UT transducer to a discontinuity can be determined by the length of time it takes sound to travel from the transducer to the discontinuities and ____.
back
In UT testing, when a evaluation discontinuities, the height of an indication on CRT can be called indication ______.
Amplitude
Indication Amplitude is not related to the shape of discontinuity. true or false
False. it indicates the height only, not the depth.
Indication amplitude is not related to the size of a discontinuity
True.
Indication Amplitude is not related to the orientation of discontinuity.
False. is a detection of discontinuity.
The term ______ refers to the detection of particle movement in an UT wave.
Wave mode
There are ____ wave modes presented.
4. 1- Longitudinal 2- shear wave 3- Rayleigh wave 4- Lamb wave
Transverse wave are also known or refers to as _____ waves.
Shear
The _____ mode of vibration cause particle to move back and forth parallel to the direction of wave propagation.
Longitudinal
The (longitudinal) mode of vibration will provide greater penetration power than the transverse mode of vibration. true or false?
True
Transverse wave can be generate at different angles by changing (incidence angle) of the sound striking the surface of the material. True or False
True
lambda = v/f is the formula to calculate wavelength. true or false?
True
In UT testing, as wave length decrease, ______ increases.
sensitivity
Transverse waves travel at approximately half the velocity of longitudinal wave because of this , the wave length generate by transverse waves will be ______ than the wave length generated by longitudinal wave of the same frequency.
TRUE OR FALSE
Shorter.
TRUE.
Rayleigh waves have a lower velocity than traverse waves. true or false?
True
The velocity of plate waves is determined by the frequency of the transducer, the thickness of the material, the angle of the incidence, and the type of material. true or false?
True
UT test sensitivity is only slightly affected by the transducer used for the test. True or False?
True
The numbers of pulses per unit time generate by the clock timer circuit of UT instrument_______
Pulse repetition mode
The clock timer provides electrical energy too both the the transducer and sweep generator in an UT instruments. True or False?
True
Low voltage signals generated by the transducer Piezoelectric elements are Amplified by the ________.
Receiver Circuit.
A ______ in an instruments is similar to a Picture to a t.v
Cathode Ray Tube
The damping control on an UT instrument enables the UT technician to change the duration of the pulse applied to the Piezoelectric element. true or false
True.
Increasing it will decrease penetration and increase resolution.
The gain control is used to increased or decreased the intensity of the sound of the material being tested.
true or false ???
False.
The gain control is used to indicate the comparison adjustment discontinuity size comparison.
The ______ control on an UT instrument can affect the vertical linearity of the instrument.
Reject.
The ________ of the Piezoelectric in an transducer determines the resonant frequency of the transducer.
Thickness.
Electronic compensation for attenuation of sound energy in the material can be accomplished with a ______.
DAC ( Distance Amplitude Correction)
Two control essential to the calibration of the sweep are the _____ and _________ control.
Delay and Range
________ control are used as an AID in monitoring a specification of the sweep.
Gate.
______ is a unit of measured associated with sound intensities.
Decibels or Db
The horizontal line near the bottom of the CRT screen may be refracted to as the time base line or ______.
Sweep display.
The first natural Piezoelectric transducer element?
Quarts
Ferromagnetic material are commonly referred to as ____ ceramics.
Polarized.
QUARTS CRYSTAL were prepared for use by cutting them in one of two planes. true or false
true
The _____ crystal provides a longitudinal mode or vibration, and the _____ provided a Transverse mode of vibration.
x-cut and Y-cut
To improve existing Piezoelectric properties ferrous-electric materials are _____.
Polarized.
Two commonly used ferrous-electric material are _____and ______.
Berrium titanate and Lead Zirconate
Lithium Sulphate is a natural Piezoelectric material, but is highly _____ in water and is slightly prone to aging.
Soluble.
The amount of dampening material used in transducer construction is very important to the operating efficiency of the transducer. highly dampened transducer will ______.
Provide better resolution.
Lucite wedges usually have serrations cut on the outer surface. the purpose of these serration is?
TO eliminate reflections that may produced confusion indications on the cathode ray tube (CRT)
Couplants are used between delays, wedges, and surface of material to eliminate air which will not support UT vibration. True or False?
True
Dual Elements Transducer are used to ______ .
Increase near surface resolution.
Pain brush Transducer have very large element dimensions, this type of transducer is very effective for?
Decreasing inspection time, large surface areas can be inspected and laminar Discontinuity may be detected.
As UT Propagate through a specimen, three areas will be formed in the beam, the are the _____zone, the near zone and the far zone
Dead zone
Delays or Dual element transducers are used to increased near surface resolution. TRUE OR FALSE
True
Within a given material near zone length will increase as transducer Diameter and Frequency are increased. TRUE OR FALSE
TRUE
Find the near zone length using a .25 Diameter 2,25 MHZ straight beam transducer (material- steel) ______
.153
The length of the dead zone can be approximated by observing the position of the ________.
Initial Impulse
Reflectors of the same size / located in the near zone could show a difference in amplitude on CRT. This could indicate that the reflectors were at the ____and___ intensity ares of the near zone.
High and Low
The area of maximum acoustic pressure denotes the end of the near____
Zone
The portion of the UT beam that extend beyond the near zone and continues until UT is attenuate or reflected is referred to as the ________.
Far Zone
As the Frequency and Diameter of the transducer are increased, Beam Spread is _______.
Decreased
Calculating the following, the full beam spread in steel is ____ using a 5’ x 5.0 MHZ straight Beam transducer.
12.8 degree
As finite reflector are at greater depths in the far zone, their amplitude response will decrease, not only as function of the beam attenuation, but also the result of _______.
Beam Spread
Controls used to calibrate the Horizontal display of A-scan UT instruments are instrument Delay and sweep controls. TRUE OR FALSE
TRUE
When calibrating the horizontal Display for A-scan presentation, the leading edges of _____. Surface indications are observed while adjusting the delay and sweep controls.
BACK.
The sweep is divided into _____ major division marked and numbered on the face of the CRT.
10.
The face of the CRT also has ________ minor divisions marked on it.
50
After calibration of the Horizontal Display, the leading edge of the initial impulse should be precisely aligned with the ‘0’ on the face of the CRT. TRUE OR FALSE
FALSE
The sweep of an UT instrument, calibrated for thickness measurement of steel pipe, would require recalibration before thickness measurements could be accurately made on aluminum casting. True or False
TRUE
The sweep calibration used for inspecting half-inch steel plate could also be USED to inspect a ten-inch thick section of a steel casting. TRUE OR FALSE?
FALSE
The longitudinal velocity of sound in steel is ______
.23X10^6
The longitudinal velocity of sand in Lucite is____
.105x10^6
repetitive indications on a CRT that correspond to the back surface of a part are called ______
Multiples
_____ can be described as an exhibited constant relationship between echos.
Linearity
The electronic performance of UT instruments must be checked periodically to assure accurate and _____presentation.
Linear data
The relationship between the displayed thickness and the true material thickness is used to verify ______ linearity.
Horizontal
Nonlinear horizontal sweep will provided incorrect _____ Data during UT inspections.
DEPT
_____ Linearity can be checked by displaying two echoes on the CRT SCREEN, WITH ONE 50% of the other and decreasing the instrument gain in 2 Db increments while checking to see that a 2 to 1 relationship between echos is maintain.
Vertical
Proper_______linearity will insure accurate Db comparison from one discontinuity to another.
Amplitude Control
If an UT instrument does not meet the linearity requirements of the code or specification, the inspector should immediately adjust the instrument before continuing the inspection. true or false
FALSE.
These adjustment should be made by an instrument manufacture Representative or a reputable calibration service.
DAC curve are a means of _________ compensating for loss of amplitude over an extended material dept.
Graphically
Proper _______ linearity will insure accurate Db comparison from one discontinuity to another.
Amplitude control
_____are constructed by peaking echos from artificial reflectors located at different depths in the type of material to be inspected.
DAC
The highest point on a CRT Screens a displayed echo will reach is often called a ___________
DAC Curve
In UT testing _____ referrers to the bending or change in direction of an UT Wave.
Refraction.
The changing from one mode of particle vibration to another is termed _______.
Mode conversion
The percentage of sound reflected at an interface between two material is related to the _____ ratio of the two material.
Acoustic Impedance
If UT strikes an interface between two materials at an angle of 35 degrees from normal, the reflected sound will be _____ degree from normal
35
generate two different waves modes in a test material. true or false?
true
write Snell’s law:
sine @1/sine@2= V1/V2
Snell’s law is commonly used to calculate the angle of the ___________ sound beam.
refracted
WHEN USING SNELL’S LAW THE ___________ VELOCITY IN THE FIRST MATERIAL IS ALWAYS USED FOR V1.
Longitudinal
The incident angle required to refract a longitudinal wave to 90 degrees from normal, is called the _____angle.
first critical
The incident angle required to refract a transverse wave to 90 degrees from the normal is called the ____angle.
second critical
whenever the incidents is between the ____ angle, only shear waves will be generate in the test piece.
critical
The point where the center of the UT beam leaves the Lucite shoe in angle beam testing is called the _____
Index point
The index point must be marked on an angle beam transducer so it can be used as a reference point for ____measurements made during an inspection.
Surface
the index point of a transducer may change as the contact surface of the transducer wear down. true or false?
True
The index point of an angle beam transducer must be located before the refracted angle of the transducer can be determined. true or false?
true
when using an IIw type 2 block, the refracted angle of the transducer is determined by peaking an indication from the ‘0.60’ hole in the block. True or false ?
False.
couplet angle beam transducer in position 2’
To accurately located discontinuity, it is necessary to know the true refracted angle of the transducer.
TRUE
A clear back surface reflection from the test pieces is critically important in order to performed an angle beam inspection. true or false?
False
To accurately locate a discontinuity using angle beam inspection techniques, sound path distance, surface distance and dept in the material must all be considered. true or false?
true
Only IIW calibration blocks may be used for angle beam inspection calibration. true or false?
False.
as long it meet AWS standards, you can use a variety of block.
The term used to described the true configuration of an UT beam is _______.
Beam profile
UT test data can be display in ______ different formats.
3
_____presentation enables the technician to determine the depth and size of a discontinuity.
A-scan
C-scan presentation provides the technician with ____ view of the specimens.
plan
_____ are usually interfaced to c-scan instrumentation to provide a permanent record of the inspection.
paper recorder
B-scan and C-scan presentations are commonly used together to provide depth information not available from the C-scan paper recorder. true or false?
False.
C-scan instrument commonly include the use of an A-scan CRT. This provide dept information not variable from the C-scan paper recorder.
Paper recorders used with with UT equipment provides either a _____ or _____ printout.
positive or negative
____ presentation in UT testing provides the technician with a cross-sectional view of the material being tested.
B-scan
A-scan presentation make use of a long persistence cathode ray tube screen. false or true?
False.
a type of display presentation that provides Amplitude and Time distance info.
Positive print recording devices display indications as printable line. true or false?
true
artificially provided discontinuity used for calibration purposed in UT testing are often called ______.
reference reflections.
