Non destructive testing

Question 1

non- destructive testing is sometimes referred to as ________________ or ___________________

Answer 1

non-destructive inspection (NDI) or non-destructive examination (NDE)

Question 2

the five most common non-destructive testing methods are

Answer 2

visual inspection, dye penetrant, magnetic particle, ultrasonics and radiography

Question 3

_________ is used to detect discontinuities open to the surface of solid and non-porous material

Answer 3

liquid penetrant testing (LPT)

Question 4

A distinct advantage of the liquid penetrant is that it can surface defects in a wide variety of materials including?

Answer 4

metals, glass, ceramics and plastics

Question 5

the major limitation of liquid penetrant inspection is that it can only detect imperfections that are ______

Answer 5

open to the surface

Question 6

there are two basic types of liquid penetrants ________ and _________

Answer 6

fluorescent and visible

Question 7

because of the vast differences among applications for liquid penetrant inspection, the systems are broadly classified as

Answer 7

the water-washable system
the post-emulsifiable systems
the solvent-removable systems

Question 8

_________ are liquid used to make excess oily penetrant on the surface of a workpiece wate-washable

Answer 8

emulsifiers

Question 9

Fluorescent penetrant testing detects surface imperfections such as

Answer 9

surface cracks in castings, welds and carbide tools,
shrinkage in castings and hot forgings, and
cracks in turbine blades and ceramic insulators

Question 10

_____________ is a process used to detect surface and subsurface discontinuities, usually at depths not greater than 6mm. the process is limited to ferromagnetic materials and is commonly used on welds, large forgings, castings and other parts with rough surfaces

Answer 10

Magnetic particle inspection

Question 11

the ___________________ is designed so water alone can wash the penetrant from the surface of the workpiece without a separate emulsification step.

Answer 11

water-washable penetrant system

Question 12

________________ that are not water-washable are employed to ensure detection of minute discontinuities in some material

Answer 12

high-sensitivity penetrants

Question 13

operations involved in the post-emulsifiable system

Answer 13

liquid penetrant, emulsifier, and developing

Question 14

there are two types of emulsifiers?

Answer 14

oil-based and water-based

Question 15

oil-based emulsifiers function by ____________

Answer 15

diffusion

Question 16

the rate at which it diffuses into the oil penetrant establishes its _________

Answer 16

emulsification time

Question 17

dry developers consist of ____________

Answer 17

fine, amorphous silica powder

Question 18

you can either sprinkle the workpiece with dry iron powder or submerge it in a ________

Answer 18

liquid with suspended iron particles

Question 19

____________ are available on various colours for contrast reasons

Answer 19

dry powder

Question 20

the __________ suspended in the liquid solutionare fluorescent

Answer 20

iron powders

Question 21

for flaws to be revealed, the magnetic field must be oriented at ___ to the direction of the defect

Answer 21

90degree

Question 22

a straight piece of ________ has a pole at each end

Answer 22

magnetized material

Question 23

because of magnetic lines of force within the bar magnet run the length of the bar, it is said to be ________________ or to contain a _____________

Answer 23

longitudinally magnetized / longitudinal field

Question 24

an electromagnet loses its magnetism when the current is shut off, except for a very small amount called _____________

Answer 24

residual magnetism

Question 25

for increased visibility, manufacturers coat particles with _______________

Answer 25

fluorescent pigment

Question 26

a ___________ is a convenient source of ultraviolet light.

Answer 26

mercury vapour lamp

Question 27

this type of lamp emits light that has a spectrum of several intensity peaks within a wide band of ____

Answer 27

wavelengths

Question 28

_____________is the ability of a material to absorb light energy at one frequency and emit light of a different frequency

Answer 28

fluorescence

Question 29

since _____ inclusions or holes aree less dense, the radiation passes through those areas more easily. that portion of the film is exposed more and is darker when the film is developed

Answer 29

slag

Question 30

the two criteria that measure the quality of the radiograph are cantrast and definition ________ refers to different degrees of darkening on the film, which depends on the amount of radiation absorbed by different sections of the specimen under examination

Answer 30

contrast

Question 31

__________ refers to the sharpness with which the image is projected on the film

Answer 31

definition

Question 32

ultrasontic testing is routinely done on bolts and pins to a _____________

Answer 32

length of 20 feet

Question 33

if a defect such as a slag inclusion is present the pulse of sound is reflected back to the transducer, picked up by the transducer and displayed on an _____________

Answer 33

oscilloscope

Question 34

ultrasonic testing is used to measure the wall thickness of mertials in corrosive service or to determine plate thickness during fabriction. thicknesses are measured to an accuracy of ___ by measurung the length of time required for a sound beam to travel thrugh the test piece

Answer 34

1%

Question 35

__________ is one of the most widely used methods of non-destructive inspection.

Answer 35

ultrasonic inspection

Question 36

a _____ transfers the mechanical vibration energy in the ultrasonic waves to the test piece.

Answer 36

couplant (a gel substance, or oil or water)

Question 37

_______ it can be used to test for surface and subsurface defects, irregularities and coating thicknesses, including deposits and sludge

Answer 37

eddy current testing

Question 38

__________ are liquids used to make excess oily penetrant on the surface of a workpiece water-washable

Answer 38

emulsifiers

Question 39

there are two types of emulsifiers

Answer 39

oil-based and water-based

Question 40

oil-based emulsifiers function by

Answer 40

diffusion

Question 41

the rate at which it diffuses into the oil penetrant establishes its

Answer 41

emulsification time