Chemical, water-base cleaners are often used for very dirty, greasy parts. If used:
C. The surface must be thoroughly rinsed free of any residue.
Generally, vapor degreasing is considered to be one of the best methods of preparing a part for ` liquid penetrant inspection because:
a. it totally removes all surface contaminants.
b. The solvent vapor removes all petroleum based materials
c. The method is easily adapted to virtually any size of the part
d. The solvent vapor removes all inorganic soils
b. The solvent vapor removes all petroleum based materials
When penetrant is applied to parts by dipping, the parts should be:
a. left in the tank during the entire dwell time.
b. Set aside until the dwell time is up
c. Placed on a rack designed to return any excess drainage to the dipping station
d. Placed in the alkaline solvent rinse tank immediately.
c. Placed on a rack designed to return any excess drainage to the dipping station
enetrant stations that have reservoir tanks with recovery systems incorporated:
a. should have an agitation system because penetrants are homogeneous
b. should have an agitation system to prevent the settling of possible contaminants
c. do not need an agitation system as penetrants are pasteurized.
a. should have an agitation system because penetrants are homogeneous
When removing penetrant from the surface by spray water wash, penetrant in a crack would be harder to remove if it has:
a. low viscosity
b. high viscosity
c. medium viscosity
d. viscosity is not important
b. high viscosity
he most desirable objectives governing the cleaning operations when removing surface penetrant are to:
a. remove little penetrant from defects and a minimum of residual penetrant from defects and a minimum of residual penetrant remaining on the surface
b. remove little penetrant from a defect and no residual penetrant remaining on the surface.
c. Remove no penetrant from defects and leave minimum of residual on the part surface.
d. Remove no penetrant from defects and leave no penetrant on the part surface.
d. Remove no penetrant from defects and leave no penetrant on the part surface.
The best method of removing the excess water-washable penetrant is to:
A. Use a hose and nozzle with forceful droplets
When removing excess post-emulsifiable penetrant in a production situation involving small irregularly-shaped parts, one may use a:
D. Strong forceful spray
The sensitivity of wet developers can be seriously impaired:
D. When the thickness of the coating becomes too heavy.
When is a non-aqueous wet developer generally preferred?
B. when it is essential to obtain as smooth and as even a coating as possible
The best method of drying after the application of a wet developer is normally:
D. Rapid drying with circulating hot air at 77°-107°C (170°-225°F)
Removal of residual penetrant or developer materials by a suitable post-cleaning technique is advantageous in which of the following cases?
C. where it could interfere with subsequent processes or with service
Post-cleaning is particularly important where residual penetrant or developer materials may combine with other materials in service to produce:
A. corrosive action
Post-cleaning should be performed:
C. as soon as possible because the materials will be easier to remove
When using post-emulsifiable fluorescent penetrant on small parts where sulfur or chlorine residual is deemed harmful.
A. Low sulphur and low chlorine penetrant materials should be used and the part should be post-cleaned in an automatic detergent wash.
“Eyeball fluorescence” should be considered when arranging black light for testing, because direct or reflected black light shining into the inspector’s eyes:
B. even though harmless, can become extremely annoying and will impair inspector effectiveness
Residual acids and chromates are more detrimental to the fluorescent water-wash process than other processes because:
D. acids and oxidizing agents react with the fluorescent dyes only in the presence of water
Due to the nature of penetrant material, most methods have which of the following adverse effects on operator health?
B. Penetrant methods include materials which can cause dermatitis if proper precautions are not observed.
Which of the following is an advantage of post-emulsifiable methods over water-washable methods?
C. They usually exhibit higher sensitivity to tight cracks
When compared to other methods, which of the items below are disadvantages of water-emulsifiable visible dye methods?
C. test time
he type of penetrant to be used on an investment casting should be:
B. Post-emulsifiable fluorescent for maximum sensitivity and water washability.
Which of the following techniques has been found to be effective for aiding penetration in certain instances in commercial application?
A. vibration
a. locate fine cracks in teeth prior to the availability of X-rays
b. locate defects in artificial teeth prior to mounting them
c. verify questionable information gathered from X-rays
d. identify the filling material
b. locate defects in artificial teeth prior to mounting them
There is a variety of equipment available for precleaning parts prior to penetrant application. Of the following, the recommended method, if practical, is:
C. vapor degreasers
If modular equipment has been obtained for a penetrant inspection system using fluorescent post-emulsifiable penetrant and wet developer, the dryer should be placed:
A. after the developer tank
In a modular equipment system using a water-washable fluorescent penetrant and dry developer, black light should be available:
D. at the wash station
When a large number of parts are inspected using dry developer that is applied by dipping, the tank should be equipped with:
D. an exhaust system
Filters for black light effectively remove:
C. visible light from the energy given off by the mercury arc
Super-bright fluorescent penetrants may be:
C. more sensitive in dim daylight than color contrast penetrant materials
The use of high power spot bulbs for color contrast penetrants:
B. should be avoided as too much glare may occur
A good penetrant must be:
D. inert with respect to the materials being tested
Wetting ability is measured by the:
D. contact angle
Which of the following functions does a developer perform?
D. “blots” the penetrant by drawing it out of discontinuities
The method that uses a color contrast penetrant in conjunction with a developer containing a low intensity fluoragent is called:
A. reversed fluorescent method
When inspection using fluorescent penetrant methods, indications will appear as a:
A. brilliant yellow-green glow against a deep violet-blue background
A visible dye indication will usually appear as a:
B. red color against a white background
When the reversed fluorescent method is used and inspection is performed under black light, indications will show up as:
B. dark spots or lines against a lightly glowing background
If an indication reappears after the original developer has been removed and another coat is applied, the discontinuity:
C. contains a reservoir of penetrant
If, upon reprocessing, a faint indication fails to reappear, what could be the cause?
A. it was probably a false indication
A network of interconnecting jagged lines appearing in hard fired, unglazed ceramic products would be an indication of:
A. thermal shock
Porosity indications in ceramics would appear:
C. essentially the same as porosity indications in metals
When inspecting glass and looking for very fine cracks, the preferred method is:
C. electrified particle
When inspecting a hard fired ceramic that is very porous, the best inspection method would be the:
D. filtered particle method
A partially welded forging lap would probably:
A. appear as an intermittent line
A ragged line of variable width and numerous branches on castings caused by a difference in cooling rates between thick and thinner sections, would most likely be an indication of:
D. hot tear
A deep crater crack will frequently appear as a:
B. rounded indication
he forces generated by capillary attraction caused a liquid to rise spontaneously in a capillary tube. These forces are also involved in the:
C. entry of a liquid into a crack.
Viscosity has a considerable effect on some of the practical aspects of the use of penetrant. It is an important factor in the:
C. speed with which a penetrant will enter a defect
One of the two most important properties of a good penetrant is wetting ability. Wetting ability is :
B. measured by contact angle and is not related to surface tension.
To make water a relatively good penetrant:
B. Water is a good penetrant and no additives are needed
A penetrant that will spread over the surface of the test area in a smooth, even film despite a small amount of surface contamination is said to have:
C. wetting ability
The sensitivity of two penetrants for crack detection is best compared by:
D. using cracked aluminum blocks
For post-emulsifiable penetrants, a good method for establishing emulsifying time is by:
B. experimentation
A newly mixed batch of wet developer should:
A. stand for 4 to 5 hours prior to use
The test used to measure the sensitivity of a penetrant to water contamination based on the amount of water is the:
D. water tolerance test
When performing an evaluation of the fluorescent ability of a penetrant, the value that is normally sought is the:
C. relative amount of light emitted by the fluorescent material compared to other penetrants.
he most accurate method for evaluating quantitative values for the emitted light of fluorescent materials is the use of a:
D. spectrophotometer
The ability of an indication to be seen can be assigned a value called the contrast ratio. This ratio is based on the amount of:
D. Light reflected by the background as opposed to the amount of light reflected by the dye
The contrast ratio of a red dye penetrant to a white developer is normally about:
C. 6 to 1
Cracked plated strips are sometimes used to compare sensitivity. These plates usually have a brittle iron plating and are bent on:
A. cantilever and radial bend dies
If a cantilever bending die is used to bend a plated strip, the cracks produced will:
D. closer together and tighter near the clamped end
The test object and standard penetrant materials should be within a particular temperature range. One of the reasons an excessively cold penetrant is undersirable is that as the temperature becomes lower:
A. the viscosity increases
f the surface temperature of the test part is excessively hot, the:
B. penetrant may loose some of its more volatile materials
Which of the following is a criterion for a good dryer?
B. the ability to heat the part to an optimum temperature in a minimum of time so that the part is both dry and warm as promptly as possible.
What are the two most important properties that determine whether a liquid will have high penetrating ability?
A. density and surface tension
Where pre-cleaning is necessary and a residue-free solvent is used, which of the following is observed?
D. the solvents are suitable for removing grease and oils, but are generally not adequate if solids are imbedded in void areas.
When utilizing the fluorescent post-emulsifiable penetrant method and performing the rinse cycle, which of the following will prevent over-rinsing?
C. discontinue the rinse as soon as the surface penetrant is removed from the part
