Liquid Penetrant Testing Method Level 3

27. The use of 100 watt spot bulbs with a plain filter for color contrast penetrants produces:

a. a high intensity narrow beam

25. When a large number of parts are inspected using dry developer that is applied by dipping, the tank should be equipped with:

a. an exhaust system

13. Postcleaning should be performed:

a. as soon as possible if the material is susceptible to corrosion

30. Which of the following functions does a developer perform?

a. blots the penetrant by drawing it out of discontinuities

7. When removing excess postemulsifiable penetrant in a production situation involving relatively large irregularly shaped parts, you may use a:

a. coarsel spray

33. If an indication reappears after the original developer has been removed and another coat is applied, the discontinuity:

a. contains a reservoir of penetrant

12. Postcleaning is particularly important where residual penetrant or developer materials may combine with other materials in service to produce:

a. corrosive action

42. The forces generated by capillary attraction cause a liquid to rise spontaneously in a capillary tube. These forces are also involved in the:

a. entry of a liquid into a crack

47. For postemulsifiable penetrants, a good method for establishing emulsifying time is by:

a. experimentation

38. When inspecting a hard fired ceramic that is very porous, the best inspection method would be the:

a. filtered particle method

51. A method for evaluating quantitative values for the emitted light of fluorescent materials is the use of a:

a. fluorometer

21. Which of the following techniques has been found to be effective for aiding penetration in certain instances in commercial application?

a. heating the part

28. A good penetrant must be:

a. inert with respect to the materials being tested

34. If, upon proper reprocessing, a faint indication fails to reappear, what could be the cause?

a. it was probably a false indication

44. One of the two most important properties of a good penetrant is wetting ability. Wetting ability is:

a. measured by contact angle and is not related to surface tension

16. Residual acids and chromates are detrimental to the fluorescent processes because:

a. the fluorescent dyes may be decomposed. resulting in weak or faint test indications

35. A network of interconnecting jagged lines appearing in hard fired, unglazed ceramic products would be an indication of:

a. thermal shock

11. Removal of residual penetrant or developer materials by a suitable postcleaning technique is advantageous in which of the following cases?

a. where it could interfere with subsequent processes or with service

53. The contrast ratio of a red dye penetrant to a white developer is normally about:

b. 33 to 1

23. If modular equipment has been obtained for a penetrant inspection system using fluorescent postemulsifiable penetrant and wet developer, the dryer should be placed:

b. after the developer tank

24. In a modular equipment system using a water washable fluorescent penetrant and dry developer, ultraviolet light should be available:

b. at the wash station

36. Porosity indications in ceramics would appear:

b. essentially the same as porosity indications in metals

With all other factors the same when removing penetrant from the surface by spray water wash, penetrant in a crack would be harder to remove if, it has:

b. high viscosity

56. Which of the following is a criterion for a good dryer?

b. it has 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

55. If the surface temperature of the test part is excessively hot, the:

b. penetrant may lose fluorescent brightness as the dyes are degraded

17. 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

19. When compared to other methods, which of the items below are disadvantages of water emulsifiable visible dye methods?

b. portability

41. A deep crater crack will frequently appear as a:

b. rounded indication

54. The test object and standard penetrant materials should be within a particular temperature range. One of the reasons an excessively cold penetrant is undesirable is that as the temperature becomes lower:

b. the viscosity increases

18. Which of the following is an advantage of postemulsifiable methods over water washable methods?

b. their sensitivity is easier to control

46. The sensitivity of two penetrants for crack detection is best compared by:

b. using cracked aluminum blocks

9. When is a nonaqueous wet developer generally preferred?

b. when it is essential to use the most sensitive developers

8. The sensitivity of wet developers can be seriously impaired:

b. when the thickness of the coating becomes too heavy

31. When inspecting using fluorescent penetrant methods, an indication will appear as a:

c. brilliant yellow green glow against a deep violet blue background

29. Wetting ability is measured by the:

c. contact angle

59. When utilizing the fluorescent postemulsifiable penetrant method and performing the rinse cycle, which of the following will prevent overrinsing?

c. discontinue the rinse as soon as the surface penetrant is removed from the part

15. Ocular fluorescence should be considered when arranging ultraviolet lights for testing, because direct or reflected ultraviolet light shining into the inspector's eyes:

c. even though temporary, can become extremely annoying and may impair inspector effectiveness

40. 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:

c. hot tear

14. When using postemulsifiable fluorescent penetrant on small parts where sulphur or chlorine residue is deemed harmful:

c. low sulphur and low chlorine penetrant materials should be used and the part should be postcleaned in an automatic detergent wash

When penetrant is applied to parts by dipping, the parts should be:

c. placed on a rack designed to return any excess drainage to the dipping station

20. The type of penetrant to be used on an investment casting should be:

c. postemulsifiable fluorescent for maximum sensitivity and water washability

32. A visible dye indication will usually appear as a:

c. red color against a white background

50. 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

22. There is a variety of equipment available for precleaning parts prior to penetrant application. Of the following, the recommended method for removing the oil phases, if practical, is:

c. vapor degreasers

26. Filters for ultraviolet lights effectively remove:

c. visible light from the energy given off by the mercury arc

45. 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

5. The most desirable objectives governing the cleaning operations when removing surface penetrant are to remove:

c.no penetrant from defects and leave a minimal of residual penetrant on the part surface

39. A partially welded forging lap would probably:

d. appear as an intermittent line

10. The best method of drying after the application of a wet developer is normally:

d. drying with circulating air at a maximum of 71 °C (160 °F).

37. When inspecting glass and looking for very fine cracks, the preferred method is:

d. electrified particle

52. 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

43. Viscosity has a considerable effect on some of the practical aspects of the use of a penetrant. It is an important factor in the:

d. ratae with which a penetrant will drain off a smooth surface

48. A newly mixed batch of wet developer should:

d. stand for 4 to 5 h prior to use

57. What are two very important properties that determine whether a liquid will have high penetrating ability?

d. surface tension and cosine of the contact angle

58. Where precleaning 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 embedded in void areas

6. The best method of removing the excess water washable penetrant is to:

d. use a hose and nozzle with a coarse spray

49. 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

Generally, vapor degreasing is considered to be one of the best methods of preparing a part for liquid penetrant inspection because:

the solvent vapor removes all petroleum based `tom materials

Chemical cleaners are often used for very dirty, greasy parts. If used:

the surface must be thoroughly rinsed free of any residue