NDT Flashcards
0
Q
Liquid penetrant
A
- enters flaw through capillary action
- area around flaw needs to be cleaned at least 1” around
- widely used in leak detection in welded thin walled vessels
1
Q
Eddy current
A
- only one that needs A/C
- very good for checking surface and subsurface cracks beneath paint
- very fast & cheap
- pieces can be non-magnetic and conductive
- coil is the basic component
2
Q
Solvent removable
A
-dye penetrant used for small area of a work piece
3
Q
Fluorescent dye penetrant
A
- requires ultra violet light
- does not detect internal flaws
4
Q
Magnetic particle inspection
A
- Sprinkle workpiece with dry iron powder or submerge in a liquid with suspended iron particles
- depth of 1/4”
- electric current is used to magnetize,but regular magnets can work as well
- 90 degrees or right angles to the defect
- portable equipment
5
Q
Dwell time
A
-Time a penetrant or developer is in contact with a surface
6
Q
Discontinuity
A
-interruption in normal structure such as crack, seam, porosity
7
Q
Contrast in X-ray
A
-different degrees of darkening on the film
8
Q
Definition in X-ray
A
-sharpness the image is projected on the film
9
Q
Destructive testing
A
- tensile
- compressive
- torsion
- fatigue
- hardness
- impact
10
Q
Non-destructive
A
- visual
- dye penetrant
- magnetic particle
- ultrasonic
- radiography
11
Q
Radiography
A
- Electromagnetic energy
- Uses gamma & X-ray
- can be used for thick materials
12
Q
Ultrasonic
A
- Up to 20ft
- High frequency sound waves between 20,000 cycles per second and 10,000,000
- for longitudinal & shear waveforms
13
Q
Penetrameter
A
- Measures quality of radiography
- a plate with 3 holes in it 2% of the thickness of the specimen
14
Q
Ultrasonic sound waves
A
- Electric pulses generated from the crystals and reflects back
- highly sensitive, but rough or small pieces are hard to test
