Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MEC302-Paddy > NDT > Flashcards

NDT Flashcards

1
Q

Which examination tests are used for surface cracks? (5)

A
  1. Visual and optical
  2. Liquid penetrant
  3. Magnetic particle
  4. Leak
  5. Hydro Proof
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which examination test can be used on subsurface cracks?

A

Electromagnetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which examination methods fall under ‘volumetric methods’?

A
  1. Radiography
  2. Ultrasonic testing
  3. Acoustic emission testing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the aim of non-destructive examination?

A

To use non-invasive techniques to determine the integrity of materials, components or structures, or to quantitively measure some characteristics of an object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the uses of non-destructive examination techniques?

A

-Flaw detection/evaluation
-Location determination
-Leak determination
-Dimensional measurements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the general process of visual/optical testing?

A

Visual examiners follow procedures.
Some procedures compare workmanship samples with production parts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the disadvantages to visual and optical testing?

A

-Not good for large areas with small cracks/defects
-Can become expensive when using lighting, microscopes, mirrors, boroscopes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How can visual and optical testing be improved?

A

-Take videos/photos for comparison
-Use image recognition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the general process of liquid penetrant testing?

A

Object is coated with dye
Excess dye is removed from the surface
Dry developer is applied, drawing penetrant out of imperfections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why would visible dyes be used in liquid penetrant testing?

A

The vivid colour contrasts with the developer, so ‘bleedout’ is easy to see

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why would fluorescent dyes be used?

A

Ultraviolet light makes them fluoresce, so imperfections can be seen easily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is liquid penetrant testing used on?

A

Microscopic cracks - dye gets into cracks by capillary action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is an extra advantage of liquid penetrant testing?

A

It gives an indication of how deep the crack is - more dye will get into a deeper crack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the general process of magnetic particle testing?

A

Magnetic field is induced in a ferromagnetic material
Surface is dusted with iron particles
Surface imperfections distort the field and concentrate iron particles near imperfections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What must be taken into account with the magnetic field in magnetic particle testing?

A

It won’t pick up flaws parallel to the field. Therefore, use fields in at least 2 directions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What detecting methods are used in leak testing?

A

-Electronic listening devices
-Pressure gauge measurements
-Liquid and gas penetrant techniques
-Soap bubble test

17
Q

What is leak testing in simple terms?

A

Listening or looking for escaping fluid

18
Q

What is the general process of electromagnetic testing?

A

Electrical currents are generated in a conductive material by an induced alternating magnetic field
Eddy currents caused by imperfections/changes in conductive properties will cause changes in induced field

19
Q

Why is electromagnetic testing more versatile than magnetic particle testing?

A

It works with any material that is electrically conductive, not just ferromagnetic

20
Q

What is the general process of radiography?

A

Uses penetrating x-rays or gamma rays, directed through a part onto a film or other media
Imperfections are indicated as density changes in the film

21
Q

What are the disadvantages of radiography?

A

-Expensive
-Requires skilled personnel
-Only sees flaws perpendicular to x-ray
-Dense targets need higher energy x-rays

22
Q

What is the general process of ultrasonic testing?

A

Uses transmission of high-frequency sound waves to detect imperfections

23
Q

What is the most common form of ultrasonic testing?

A

Pulse echo

24
Q

How does pulse echo work?

A

Sound is introduced into an object and reflections are returned to a receiver from internal imperfections or geometrical surfaces

25
Q

What is the general process of acoustic emission testing?

A

When a solid material is stressed, imperfections emit emissions
They can be detected by special receivers

26
Q

What are emissions?

A

Short bursts of acoustic energy

27
Q

How can emissions be evaluated?

A

Through the study of their
-Intensity
-Rate
-Location

28
Q

What should the primary evaluation method be for any quality control program and why?

A

Visual inspection
It is inexpensive and doesn’t normally require special equipment

29
Q

Why are visual aids and gauges sometimes used in VT?

A

To make discontinuity detection easier and to measure the size of discontinuities

30
Q

What can be used if the area to be inspected is not readily visible?

A

-Boroscopes
-Torches
-Mirrors

31
Q

What qualitative measurements can be made of the weld joint?

A

-Fit-up
-Weld size
-Weld reinforcement height
-Misalignment
-Depth of undercut

32
Q

What defects on the base metal prior to welding can cause weld defects? (And can be detected with VT)

A

-Scabs
-Scales
-Seams

33
Q

What should be checked after parts have been assembled for welding?

A

-Weld joint root opening
-Edge preparation

34
Q

What is the normal sequence for a typical liquid penetrant test?

A
  1. Clean test surface
  2. Apply penetrant
  3. Wait for dwell time
  4. Remove excess
  5. Apply developer
  6. Examine surface
  7. Clean to remove residue
35
Q

What are the essential elements of radiographic testing?

A
  1. Source of penetrating radiation
  2. Record or viewing device
  3. Qualified radiographer
  4. Means to process exposed film or operate other recoding means
  5. A person skilled in interpretation of radiographs
36
Q

What does the measurement system for ultrasonic testing include?

A
  1. Pulser circuit (produces impulses to excite transducer)
  2. Receiver
  3. Gates (monitor size of received signal)
  4. Scanning systems (move transducer over fixed path)
  5. Ultrasonic transducer (produces electrical-mechanical conversion to create wave)

MEC302-Paddy (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions