basic asnt review 2nd Flashcards
the most common frequency range of acoustic emission testing is
100-300 KHZ
Types of Discontinuity that are readily detectable by acoustic emission testing are
leak, plastic deformation, growing cracks
In acoustic emission testing, the total energy loss of a propagating wave is called
attenuation
the Kaiser effect refers to
the behavior where emission will not occur until the previous load is exceeded
The felicity effect is useful in evaluating
fiber reinforced plastic components
The Kaiser effect is useful in distinguishing
mechanical noise from growing discontinues
The terms counts refers to
the number of time a signal crosses a preset threshold
The acoustic emission signal amplitude is related to
the intensity of the source
In acoustic emission testing, threshold settings are determined by
the background noise level
In acoustic emission testing , background noise can be reduced by
electronic filtering
Eddy currents are circulating electrical currents induced in conductive materials by
Alternating magnetic field
The method used to generate eddy currents in the test specimen by means of a coil most closely compared with the action of a
Transformer
Eddy current testing relies on the principle of
Electromagnetic induction
When the electrical current in an eddy current coil reverses direction the
Direction of the eddy currents in the part also reverses
In order to generate measurable eddy currents in the test specimen, The specimen must be
An electrical conductor
The magnetic field generated by the eddy currents induced in the test specimen
Opposes the magnetic field that induced the eddy currents
In eddy current testing, IACS recognized abbreviation for
International annealed copper standard
In Eddy current testing, the specimen is coupled to the test coil by
The coils electromagnetic fields
The penetration of eddy currents in the conductive material is decreased when the
Test frequency, Conductivity of the specimen, or the permeability of the specimen is increased
At a fixed test frequency, in which of the following materials will the eddy current penetration be greatest
Lead (7% IACS conductivity)
A term used to describe the effect of observed due to a change in the coupling between a test specimen and a flat probe coil when the distance of separation between them is varied is
Lift off
When testing with eddy currents, discontinuity will be most easily detected when the eddy currents are
Perpendicular to the major plane of the discontinuity
Which of the following discontinuities is easiest to detect with eddy current test (subsurface crack lying parallel, discontinuity in the center of a bar stock, radial crack extended to the surface of a 2” bar, subsurface radial crack, a surface crack parallel to eddy currents)
A Radial crack that extends to the outer surface of a 51 mm or 2 inch diameter bar
The term used to define the timing relationship involved in alternating current signals is
Phase
The impedance of the test soil can be represented by the vector some of
Inductive Reactance And resistance
Disadvantages of using a surface probe coil for the eddy current inspection of small Diameter tubing include
Slow inherent speed and mechanical problems
In eddy current testing, the term to fill factor applies to
An encircling coil
in Eddy current, Which of the following materials would be most likely used as a mounting material for a probe coil (Aluminum, plastic, copper, non magnetic steel )
Plastic
Which of the following is not a commonly used eddy current testing readout mechanism (Signal generator, meter, cathode ray tube, strip chart recorder )
Signal generator
Referenced standard used for eddy current testing ( holes and notches, natural discontinues, must be free of discontinuities)
Are not typically described in any of the above
In eddy current testing name some of the conditions that are important in selecting specimens as use for reference standard
Specimen should be the same size and shape specimens should be of the same material and same heat treat surface finish of the specimen should be the same, that if the material is aluminum the surface should be Anodized
Which of the following conditions would be the most difficult to detect when eddy current testing a rod using an encircling coil (short crack that is 10% of the diameter, 5% change in diameter, 10% change in conductivity, a small inclusion in the center)
A small inclusion in the center of the rod
The thickness of non conductive coatings on the conductive base can be most simply measured by
Observing the lift off effect caused by the Coating
Some of the products commonly eddy current tested using encircling coils are
rods, tubes, wires
it is often possible to sort various alloys of a non magnetic metal by means of an eddy current test when
There is a unique range of conductivity values for each alloy
When eddy current testing tubing with a system that includes a frequency discriminating circuit, which of the following variables would be classified as a high frequency variable
Small discontinuities
Which of the following was not a candidate for testing by the eddy current method (3” thick plate, tube with surface cracks, rod with laps and seams, tube with varying diameters)
A 4 inch thick Plate to be tested for discontinuities Throughout the plate
which systems or components are candidates for leak testing
Piping and pressure vessels and, refrigeration piping, vacuum chambers
A helium mass spectrometer is used in which of the following NDT methods
Leak testing
Which of the following is a technique of a leak testing (bubble detection, pressure change measurements, halogen sniffing)
Halogen sniffing
Potentially the most sensitive leak testing technique is the (mass spectrometer, bubble test, pressure change, liquid penetrant)
Mass spectrometer test
Establishing differential pressure between a test object and environments is an in sensual element in which of the following methods (X-ray, neutron, leak testing, gamma radiography
Leak testing
Which of the following best describes the type of leak test used when the interior of the test object is Evacuated And a tracer gas is applied to the exterior )static leak, helium test, dynamic leak, halogen leak, sniffer leak)
Dynamic leak test
Assuming no significant leakage, if the temperature increased during a pressure drop leak test, the pressure in the system under test would
Increase
If the sensitivity of the halogen leak detector is constant throughout a test, which of the following is true upon completion of the test (no leaks of certain size have gone undetected, total leak rate is less than a certain amount, the instrument and test procedure were capable of leak detection of a certain size)
The instrument and test procedure were capable of detecting leakage of a certain size during the test
All leak detection methods are dependent upon
Gas or fluid flow
In an evacuated system, sensitivity of a pressure change leak test is dependent not only on the pressure change observed, but also on the degree of out gassing. Out gassing is best defined as
The release of gas from materials in a vacuum
The tendency of a liquid penetrant to enter a discontinuity is primarily related to
Capillary forces
Liquid penetrant testing is a nondestructive test that can be used for
Locating discontinuities open to the surface
Which of the following is not a characteristic that applies the liquid penetrant testing (method can be used for on-site testing of large parts, method can be made more or less sensitive by using different penetrant material, find shallow surface discontinuities, method can accurately measure the depth of a crack or discontinuity)
This method can accurately measure the depth of a crack or discontinuity is not true
The property of the dye used in penetrant materials to emit light of a range of wavelength different from the wavelength of light that excites the emission is called
Fluorescence
When using a fluorescence post emulsifier penetrant, the length of time the emulsifier is allowed to remain on the part is critical for detecting shallow discontinuities. The optimum length of time should be
Determine by experimentation
A red penetrant indication against white background is most likely to be seen when
Visible by penetrant are used
The most widely accepted method for removing excessive water washable penetrant from the surface of the test specimen is by
Using a water spray rinse
Which of the following penetrant systems is generally considered the least sensitive (
Water washable with visible Die
There are several ways to remove excess solvent removable visible Dye penetrant. Which of the methods listed is generally regarded as the most suitable for giving accurate test results (squirt solvent with 10psi pressure, wiping with solvent soaked cloth the wipe with dry cloth, wipe with solvent damp cloth the wipe with dry cloth, wipe with dry, wipe with solvent damp cloth, then wipe with dry cloth)
Wiping with dry wipe , then wiping with solvent dampened cloth, and finally wiping with dry cloth
A problem with retesting a specimen that has been previously tested using liquid penetrant is that
penetrant residue left in discontinuities may not readily dissolve and the retest may be misleading
A commonly used method of checking the overall performance of the penetrant material system is to (determine the viscosity of the penetrant, measure the wetability of the penetrant, compare two sections of artificial crack specimens)
Compare two sections of artificially cracked specimens
The function of emulsifier in the post Emulsified penetrant process is to
React with the surface penetrant to make the penetrant water washable
Which of the following statements does not apply to developers use during penetrant testing developers are normally highly fluorescent, developers can furnish contrasting background, developers absorb or blot remaining penetrants after excess is removed)
Developers are normally highly fluorescent
The penetrant indication for a cold shut on the surface of the casting will normally be
A smooth continuous line
The penetrant indication for a crack type of discontinuity will generally appear as
A continuous line, either straight or jagged
In a penetrant test, scattered round indications on the surface of the part could be indicative of
Porosity
Which of the following are typical non relevant indications found in penetrant testing indications due to geometry or part design, nonmagnetic indications, multiple indications, non linear indications, indication on low stressed areas)
Indications due to part geometry or part design
Which of the statements below best states the results of sand blasting for cleaning surfaces to be penetrant tested (discontinuities may be closed, oil contaminates might be sealed in, the sand may be forced into the discontinuity, the operation may introduce into the part)
Discontinuities will be closed
The penetrant indication of a forging lap will normally be
A thin continuous line
Aluminum and alloyed test specimens that have been tested by the liquid penetrant method should be thoroughly cleaned after testing because
The Alkalines in wet developers and most emulsifiers could cause surface pitting , particularly in moist atmospheres
Liquid penetrants may be used for leak detection
If services are clean and both sides are accessible, penetrant is a diluted form during a hydro test, effectively by using fluorescent tracers
Which of the following is the discontinuity that might be found in rolled bar stock with liquid penetrant
Cracks or seams
anodized surfaces are usually considered poor candidates for high sensitivity liquid penetrant examination because the anodizing process produces a conversion layer that
Has a multitude of extremely small pores
Which of the following penetrant methods does not normally require a source of electricity to properly conduct a test (water washable fluorescent, post emulsified fluorescent, visible dye)
Visible dye penetrants
Which of the following statements of is true concerning penetrant testing of welds with rough surfaces (Post emulsified offers advantages over water washable, weld Surfaces must be ground flush, solvent removal process the developer would be an Aqueous suspension, Welds with rough surfaces cannot be tested
none are true
Which of the following materials cannot be tested by magnetic particle techniques (High alloy steel, tool steels, Copper alloys, ferritic stainless steel
Copper alloys
Up materials that are strongly attracted to a magnet are called
Ferro magnetic
Magnetic lines of force are orientated in which direction in relation to the direction of the magnetizing current
At right angles
Magnetizing flux is a term that relates to
The lines of force associated with a magnetic field
Subjecting a part to a magnetic field that is constantly reversing in polarity and it gradually diminishing in strength accomplishes what
The part is demagnetized
Circular magnetization is useful in the detection of
longitudinal cracks
In which magnetizing method is the current pass directly through the part, thereby setting up a magnetic field at right angles to the current flow (longitudinal magnetization, core oil magnetization, central conductor magnetization
None of these
Which of the following is a major disadvantage of using the prod method
The inspection service may be arc burned
Inspecting a part by applying the magnetic particle suspension while the current is flowing is called the
Continuous method
How is the inside diameter of the cylinder best magnetized
With a central conductor placed between contact heads
The amount of amperage used for magnetic particle inspection using the prod method is based on the
Thickness of the party and the distance between the prods
Demagnetization is of a part is usually not necessary if the part is
To be Hardened by heat treatment after inspection
Which of the following is an advantage of the dry method over the wet method (more sensitive for detecting find surface cracks, more capable of providing full service coverage on your regularly shaped parts of, it is easier to use for field inspection with portable equipment, faster when testing small parts
Easier to use for field inspection with portable equipment
Fluorescent magnetic particles are used in preference to visible magnetic particles
To increase the speed and reliability of detecting very small discontinuities
The most versatile type of magnetic particle equipment is (portable equipment, stationary horizontal machine, mobile power unit, automatic machine, field kit
Stationery horizontal machine
Magnetic particle inspection methods are recognized as superior to liquid penetrant techniques when the
Parts are painted
When using direct current, an indication is detected. What is the next logical step to determine if the indication results from a surface or subsurface condition
RE inspect using alternating current
A requirement to use magnetic particle testing on a part should also include
The procedure to be used an acceptance criteria
The statement that magnetic particle testing can be applied to plated and painted parts
May be true of flux densities are increased to compensate for the coating thickness
The best type of magnetizing current for inspection of fatigue cracks is
Alternating current
A star shaped indication was seen on the cover pass of the weld. What type of discontinuity was indicated
A crater crack
For maximum sensitivity in magnetic particle inspection of rough welds
The well bead should be ground flush with the plate surfaces
The highest intensity sources of thermal neutrons are (accelerators, nuclear reactors, cf-252 isotopes )
nuclear reactors
neutrons for fast and neutron radiography are obtainable from (Accelerators, radioactive sources, reactors)
All of these
A radioactive source to be used for neutron radiography is
cf-252
The energy of the neutron is expressed in which of the following units of measurement (Curries, roentgens, half life , electron volts)
Electron volts
A normally desirable feature of a thermal neutron beam for neutron radiography is
Low gamma radiation intensity and relatively low fast neutron intensity
Material that slows down neutrons is called
A moderator
The primary radiation mechanism for darkening X-ray film when the direct a neutron radiography processes used with gadolinium screens is
Electrons
Neutron radiography using the transfer method requires that the imaging screen
Become radioactive
Which of the following neutron radiography converter foils cannot be used for transfer or indirect radiography (Dysprosium, indium, gold, gadolinium)
gadolinium
But the most suitable film for producing neutron Radiographs are
Industrial X-ray film
materials that are exposed a thermal neutron beams
May be radioactive after exposure to neutrons has ceased
Lead is a good or poor neutron absorber
A relatively poor neutron absorber
if 0.08 inches of plastic attenuates a thermal neutron beam by a factor of two than 0.8 inches will attenuate it by approximately a factor of
1000
Materials in common usage for moderation a fast neutrons sources include
Water, plastic, paraffin and graphite
If the main reason for using neutron radiography in place of x-radiography is
The ability to image objects and materials not possible with x-rays
A photographic record produced by the passage of neutrons through a specimen onto a film is called
A radiograph
Many of the absorption differences between neutrons and X-rays indicate that the two techniques
Complement each other
The penetrating ability of a thermal neutron beam is governed by
Attenuating characteristics of the material being penetrated
The transfer exposure method is used because
It is not influenced by gamma radiation in the primary beam
Higher resolution can be achieved in direct a neutron radiography by
Increasing the L/D ratio of the culmination system
The primary advantage of using a Cf-252 source for neutron radiography is its
Portability
Quality of the results from a neutron radiographic exposure is best determined by
Image quality indicators
The radiographic image of flaws in the imaging screens can be separated from actual flaws any part being radio graphed by
Comparing a neutron radio graph of the part to a blank neutron radio graph of the same screen with no parts
For inspection of radioactive objects or those that emit gamma radiation when bombarded with neutrons, a preferable detection technique is the
Transfer technique
Neutron radiography is an excellent tool for determining
If the integrity of thin plastic material within a Steel Housing
The neutron radiography extends radiographic capability for detecting cracks and small cylinders of
Plutonium
Which of the following is not a preferred application of neutron radiography
Detecting the presence of a lead rupture diaphragm in a small aluminum safety valve assembly
The penetrating ability of and X-ray beam is governed by
Kilovoltage or wavelength
Two X-ray Machines operating at the same nominal Kilovoltage and milli amperage settings
May give not only different intensities but also different energies of radiation
Which of the following X-ray generators would produce the narrowest cone of x radiation (10 MeV,15 MeV, 25 MeV, 1 MeV,Co-60)
1 MeV
Short wavelength electromagnetic radiation produced during the disintegration of nuclei of radioactive substances is called
Backscatter radiation
Almost all gamma radiography is performed with
Tm-170
The energy of gamma rays is expressed by which of the following units of measurement
Curie
Of the following, the source providing the most penetrating radiation is the (Cobalt 60, 15 MeV BetaTron, electrons from IR - 192, 220 KVP X-ray tube )
220 KVP X-ray tube
Common sources of Neutrons for neutron radiography are
BetaTron
The difference between densities of two areas of a radiograph is called
Film contrast
The fact that gases, when bombarded by radiation, ionized and become electrical conductors make some useful and
Masks
the reason exposure time must be increased by a factor of four when the source to film distance is doubled is that the
Intensity of radiation is inversely proportional to the square of the distance from the source to the film
The most important factor in X-ray Absorption of the specimen is
The atomic number of the material
Which of the following is the probable early effect of the 25 REM radiation dose of to the whole body
Blood changes but no serious injury
Exposure to small doses of x-rays or gamma rays
Has a cumulative affect that must be considered When monitoring
Which of the following technique variables is most commonly used to adjust to object contrast (Source to film distance, milliamperage, kilo voltage, focal spot size)
All of these
A basic difference between a radio graph in a fluoroscopic image is that
The fluoroscopic image is positive whereas the radiographic image is a negative
Thin sheets of lead foil in intimate contact with x-ray film during exposure increase film density because they
emit electrons when Exposed to x and gamma radiation, which helps to darken the film
When viewing a radiograph, an image of the back of the cassette superimposed on the image of the specimen is noted. This is most likely due to
Backscatter radiation
A penetrometer is used to measure the
Quality of the radiographic technique
In film radiography, penetrometer are usually placed
On the source side of the test object
Had voltages above 400 KV, the use of lead to provide protection may presents serious problems, which of the following materials would most likely be used as a substitute (Aluminum, concrete, steel, boron, polyethylene)
Concrete
The distinctive characteristic of high voltage radiography is that
It is applicable to comparatively thick or highly absorbing specimens
Given the radiographic equivalency factors of 1.4 for a Inconel and 1. for 304 stainless, what is the approximate equivalent thickness of Inconel to produce the same exposure as a 0.15 inch thickness of 304 stainless
.11 inches (.15/1.4)
Upon completing and X-ray exposure and turning the equipment off, personnel
May enter the exposure area without fear of radiation exposure
The fact that each solid crystalline substance of produces its own characteristic X-ray pattern is the basis for
X-ray diffraction testing
When inspecting a light metal casing by fluoroscopy, which of the following discontinuities would most likely be detected
Shrinkage
For testing a 1 inch steel plate 12 inches square for laminar discontinuities, which of the following would be most effective
An ultrasonic device
a critical weld was made with a double V groove. Which technique would provide coverage with the greatest probability for detecting the most areas discontinuity
Two exposures aligned with the V groove plus and +-30 deg off of perpendicular
A fuse assembly is Being Radiographed so that measurements can be made on the film to determine A minimum internal clearance dimension , what should be factored into the dimension taken from the film
Projection magnification, unsharpness factors, precision of the x-ray beam alignment
Small electronic components are to be radiograph inspected To reveal Copper wires of 0.008 inches diameter. What would be the most effective technique
A plastic block with the radiographic thickness the equivalent of the test object, containing copper wires ranging from 0.005 inches to .015 inch diameter
ultrasonic Waves propagate through test materials in the form of
Mechanical vibrations
when an Ultrasonic beam passes through the interface of two dissimilar materials at an angle, a new angle of sound travel takes place in the second material due to
Refraction
A gradual loss of energy as ultrasonic vibrations travel through material is referred to as
Attenuation
Ultrasonic velocities are different for different materials. These differences are primarily caused by differences in the materials
Elasticity and density
The ultrasonic energy For immersion testing is transmitted to the test object as a compressional wave because
Liquids will only sustain compressional waves
When inspecting course grained materials, which of the following frequencies will generate a sound wave that will be most easily scattered by the grain structure (1.0 MHz, 2.25 MHz, 5 MHz, 10 MHz)
10 MHz
In general, shear waves are more sensitive to small discontinuities than longitudinal waves for a given frequency and in a given material because
The wavelength of shear waves is shorter than the wavelength of longitudinal waves
The ability of transducers to detect echoes from small discontinuities is the definition for
Sensitivity
Which of the following will create a resonance condition in a specimen
Continuous longitudinal waves
The display on most basic pulse echo ultrasonic instruments consists of
An A scanned presentation
In a basic pulse echo, the component that produces the voltage that activates the search unit is called
The pulsar
The primary purpose of reference blocks is to
Obtain a common reproducible reference standard
The general use of distance amplitude calibration is to compensate for
Attenuation, distance and beam spread
In area amplitude ultrasonic standard of test blocks, the flat bottom of holes in the blocks are
Different in diameter, increasing in 0.02 inch increments
The amount of energy reflected from a discontinuity is dependent on
The size of the discontinuity and the orientation of that discontinuity
The presence of the discontinuity will not produce a specific indication on the CRT screen went which of the following techniques is being used (straight beam testing, surface wave testing, angle beam testing, through transmission testing, pulse echo testing)
Through transmission testing
Lack of parallelism between the entry surface and the back surface
May result in a screen pattern that does not contain back reflection indications
Significant error in ultrasonic thickness measurement can occur if
the velocity of propagation deviates substantially from assumed constant value for a given material
In contact testing, shear waves can be induced in the test material by
Using and angle beam transducer with the transducer mounted on a plastic wedge so that the sound enters that part at an angle
The most commonly used method of produced in shear waves in the test part when inspecting by the immersion method is by
Angulating the search tube to the proper angle with respect to the entry surface of the test part
In immersion testing, proof that the search unit is normal to a flat entry surface is indicated by
The maximum reflection amplitude from the entry surface
In immersion testing, the water distance of between the search unit and the test piece
Should be this same as the water distance used during calibration
Generally, the best ultrasonic testing technique for detecting discontinuities orientated along the fusion zone in the welded plate is
An angle beam method using a shear waves
Thin sheets may be inspected for laminar discontinuities with the ultrasonic wave directed normal to the surface by observing
The multiple reflection pattern
Ultrasonic inspection of castings is occasionally impractical because of
Course grain structure
Angle beam testing of plate will often miss
Laminations that are parallel to the front surface
Reflection indications from a weld area being inspected by the angle beam technique may represent
Porosity, cracks, weld bead
An ultrasonic the test using a straight beam contact search you and that is being conducted to the thickness of a flat part such as plate. This test should detect
Laminar type flaws with major dimensions parallel to the plane of the rolled surface
The resonance technique of thickness measurement has been mostly replaced by
Linear time base pulse echo techniques
Ultrasonic testing techniques are useful in testing laminate and sandwich construction test objects for
Bond integrity
Ultrasonic techniques are frequently used to in online automatic process control applications to measure and control
The thickness of cold rolled strips, sheets and plates
Which of the following statements about field inspection applications of ultrasonic testing is true (the equipment is large and bulky, field inspections are difficult, aircraft and other field maintenance inspections require three persons, digital displays must be used for all of our inspection because of limited brightness, field inspections are limited to discontinuity detection by contact technique only, none of these)
None of these
What is considered the typical spectral range of visible light for most humans
380 - 770 nanometers
What element of the eye functions the same as the photographic plane of the camera
The retina
A surface has a diffuse reflection when
A fuzzy reflection of the light source is seen
The resolution of the human eye at a distance of about 12 inches is nearest
0.003 inches
Are routine direct visual inspection, the eye should be located at a distance
Between 12 and 24 inches
The angle the eye makes with respect to the normal inspections surface should not
Exceed 45 degrees
The minimum lighting condition recommended for detecting small cracks in welds is
500 lux
What is the name of the condition of eye adaptation to a dark environment
Scotopic vision
The spectral range of vision response in humans is
Dependent on lighting conditions
IES is the abbreviation for
Illuminating engineering society
The eye is functionally blind when it is
Moving between observation points
When looking for surface conditions, the illumination angle should be
Between five and 45 degrees, measured from the part surface
Fluorescence is defined as
Absorbing and emitting light at different wavelengths
Pillowing found when inspecting aircraft skins is usually attributed to
Expansion of corrosion products under the skin
When inspecting extrusions for excessive of draw marks under a pair of long fluorescent tubes
It is best to align the probable direction of the draw marks parallel to the tubes
The heat affected zone of carbon steel welds is made visible through the use of
etchants to enhance the visibility of the micro structure
inspection schemes to that rely on optical interference patterns include
Moire imagery, holography, Interferometry
