CWB Level 2 NDT Test Questions and
Answers7
Liquid Penetrant Testing Steps - ANSWERS-1) clean/dry surface
2) apply penetrant
3) dwell time
4) remove excess penetrant
5) apply developer
6) inspection
Small contact angle means - ANSWERS-The liquid "wets" into the solid
Large angle means poor wetting
Contact angle for a liquid can be reduced by adding - ANSWERS-A detergent (surfactant)
Titanium, Nickel alloys can be harmed by - ANSWERS-Halogens (chlorides, sulphur)
Three methods for removing excess penetrant - ANSWERS-1) water washing
2) post emulsifier
3) solvent
ASTM E-165 Standard Test Method for LPI classifies methods of LPI by: - ANSWERS-1) type of
dye
2) method of penetrant removal
3) type of developer
, 2 types of dye are - ANSWERS-Visible and fluorescent
Post emulsified penetrants require - ANSWERS-Emulsifying agent to make them water washable
Lipophilic and Hydrophilic
Used with fluorescent dye
Solvent removable penetrants utilize - ANSWERS-Volatile organic solvents
Dry quickly before the application of developer
Good for limited portability parts
Welds are most commonly examined using - ANSWERS-Colour contract , solvent removable
method
Types of developers - ANSWERS-Aqueous
Non-aqueous
Water soluble
Water suspendable
Dry powder developers are - ANSWERS-Light free flowing powders
Only used with fluorescent penetrants
Applied with powder gun, electrostatic spray or dust storm cabinet
Non aqueous developers are - ANSWERS-Developer particles suspended in volatile organic
solvent
Used with solvent removal process (spot checking welds)
Must be thoroughly agitated
Answers7
Liquid Penetrant Testing Steps - ANSWERS-1) clean/dry surface
2) apply penetrant
3) dwell time
4) remove excess penetrant
5) apply developer
6) inspection
Small contact angle means - ANSWERS-The liquid "wets" into the solid
Large angle means poor wetting
Contact angle for a liquid can be reduced by adding - ANSWERS-A detergent (surfactant)
Titanium, Nickel alloys can be harmed by - ANSWERS-Halogens (chlorides, sulphur)
Three methods for removing excess penetrant - ANSWERS-1) water washing
2) post emulsifier
3) solvent
ASTM E-165 Standard Test Method for LPI classifies methods of LPI by: - ANSWERS-1) type of
dye
2) method of penetrant removal
3) type of developer
, 2 types of dye are - ANSWERS-Visible and fluorescent
Post emulsified penetrants require - ANSWERS-Emulsifying agent to make them water washable
Lipophilic and Hydrophilic
Used with fluorescent dye
Solvent removable penetrants utilize - ANSWERS-Volatile organic solvents
Dry quickly before the application of developer
Good for limited portability parts
Welds are most commonly examined using - ANSWERS-Colour contract , solvent removable
method
Types of developers - ANSWERS-Aqueous
Non-aqueous
Water soluble
Water suspendable
Dry powder developers are - ANSWERS-Light free flowing powders
Only used with fluorescent penetrants
Applied with powder gun, electrostatic spray or dust storm cabinet
Non aqueous developers are - ANSWERS-Developer particles suspended in volatile organic
solvent
Used with solvent removal process (spot checking welds)
Must be thoroughly agitated
