CWB LEVEL 2 QUESTIONS AND ANSWERS
What are the 5 main categories for lp indications - answers-1. Continuous line
2. Intermittent line
3. Rounded
4. Small dots
5. Diffused or weak
Surface tension - answers-property of a liquid that tends to reduce the area of the
surface
Contact angle - answers-the angle that the base of a drop of water makes with the
surface it is on
If a liquid has good wetting it has a _________ contact angle - answers-small contact
angle
Capillary action - answers-tendency of water to rise in a thin tube
How are lp procedures/techniques qualified - answers-comparator block
False indications - answers-indications not associated with a discontinuity of any kind
Nonrelevent indications - answers-indications cause by features or design of material
.
Magnetic retentivity - answers-the ability of a material to stay magnetized
How do inspectors remove a materials retained flux? - answers-apply field in opposite
direction
Coercive force - answers-the strength of the reverse field necessary to bring the
induced flux to zero.
What range should the applied filed be applied to avoid saturation of a material? -
answers-30 to 70%
Electric current produces what kind of magnetic field? - answers-circular
The lines of force are _______ the strength of the applied current?
A. Proportional
B. 2x bigger
C. 2x smaller - answers-a. Proportional
, Adding a coil does what to the magnetic field? - answers-increase. It adds to the
strength of the others
Ampere-turns - answers-the relative strength of a field from a coil
2 types of magnetization in mp inspection? - answers-1. Longitudinal, and circular.
2 methods of mp inspection? - answers-1. Direct magnetization - current passes
through the part
2. Indirect magnetization - either a permanent or electromagnet is placed directly on the
part or the part is placed in and electromagnet.
How are arc strikes avoided when using prods for mp inspection? - answers-current is
not applied until both prods are on the part.
Current applied during mt inspection using prods is calculated by _______ amps for
every mm - answers-4 amps per mm or 100 amps per inch (90 to 125 amps for each 25
mm or 1 in)
Typical amp output from a yoke is? - answers-5 to 10 amps
During mt inspection an ac will magnetize the ______ of the part. - answers-surface
(skin effect)
Direct current applied during mt inspection has the ability to penetrate how far into the
material? - answers-2- 3 mm
During mt inspection which methods is more sensitive?
A. Wet
B. Dry - answers-a. Wet
Variations in permeability can arise from? - answers-1. Composition
2. Micro structure
3. Hardness
4. Heat treatment
5. Work hardening
What standard are cgsb inspectors certified to? - answers-can/cgsb 48.9712
Mp can not be used on what types of materials? - answers-1. Non ferrous
2. Austenitic stainless
3. Copper
4. Aluminum
Flux leakage field - answers-a path created between 2 new polls as a result of an
indication
What are the 5 main categories for lp indications - answers-1. Continuous line
2. Intermittent line
3. Rounded
4. Small dots
5. Diffused or weak
Surface tension - answers-property of a liquid that tends to reduce the area of the
surface
Contact angle - answers-the angle that the base of a drop of water makes with the
surface it is on
If a liquid has good wetting it has a _________ contact angle - answers-small contact
angle
Capillary action - answers-tendency of water to rise in a thin tube
How are lp procedures/techniques qualified - answers-comparator block
False indications - answers-indications not associated with a discontinuity of any kind
Nonrelevent indications - answers-indications cause by features or design of material
.
Magnetic retentivity - answers-the ability of a material to stay magnetized
How do inspectors remove a materials retained flux? - answers-apply field in opposite
direction
Coercive force - answers-the strength of the reverse field necessary to bring the
induced flux to zero.
What range should the applied filed be applied to avoid saturation of a material? -
answers-30 to 70%
Electric current produces what kind of magnetic field? - answers-circular
The lines of force are _______ the strength of the applied current?
A. Proportional
B. 2x bigger
C. 2x smaller - answers-a. Proportional
, Adding a coil does what to the magnetic field? - answers-increase. It adds to the
strength of the others
Ampere-turns - answers-the relative strength of a field from a coil
2 types of magnetization in mp inspection? - answers-1. Longitudinal, and circular.
2 methods of mp inspection? - answers-1. Direct magnetization - current passes
through the part
2. Indirect magnetization - either a permanent or electromagnet is placed directly on the
part or the part is placed in and electromagnet.
How are arc strikes avoided when using prods for mp inspection? - answers-current is
not applied until both prods are on the part.
Current applied during mt inspection using prods is calculated by _______ amps for
every mm - answers-4 amps per mm or 100 amps per inch (90 to 125 amps for each 25
mm or 1 in)
Typical amp output from a yoke is? - answers-5 to 10 amps
During mt inspection an ac will magnetize the ______ of the part. - answers-surface
(skin effect)
Direct current applied during mt inspection has the ability to penetrate how far into the
material? - answers-2- 3 mm
During mt inspection which methods is more sensitive?
A. Wet
B. Dry - answers-a. Wet
Variations in permeability can arise from? - answers-1. Composition
2. Micro structure
3. Hardness
4. Heat treatment
5. Work hardening
What standard are cgsb inspectors certified to? - answers-can/cgsb 48.9712
Mp can not be used on what types of materials? - answers-1. Non ferrous
2. Austenitic stainless
3. Copper
4. Aluminum
Flux leakage field - answers-a path created between 2 new polls as a result of an
indication
