Surface Methods – Liquid Penetrant Inspection (LPI) Exam 1 Practice

These questions are part of the practice quiz. Start practicing

• Which statement defines surface wetting?
• Which nondestructive testing method is the oldest and most widely used?
• LPI is used to reveal which type of discontinuities?
• Fluorescent dyes are designed to fluoresce when exposed to what wavelength UV?
• How is wet non-aqueous solvent suspended developer applied?
• What is the method called that used highly visible red dyes?
• Which statement is true about the advantages of wet aqueous soluble developer?
• Which pairing shows the smallest contact angle: water on silver, water on glass, water on copper, or mercury on glass?
• LPI is best described as which of the following?
• How was sensitivity increased for railway LPI?
• When does dwell time begin for wet aqueous developers?
• Methods of applying dry developers?
• When was the Zyglo system of fluorescent penetrant inspection introduced?
• Which statement best differentiates wet nonaqueous developer from other types in terms of application and results?
• What is the effect of under removal of penetrant during testing?
• What is the purpose of agitation during the immersion method?
• What year was the oil and whiting LPI method used?
• The intensity should be greater than or equal to:
• What effect does viscosity have on penetrant performance?
• What is a general statement about solvent removable penetrants?
• How are dry developers applied?
• Heat boiling off chemicals that prevent separating and gelling may result in what?
• Which technique surpassed LPI for ferromagnetic iron and steel?
• What is the effect of a closed capillary tube on capillary rise compared to an open tube?
• Visible dye colors are available in which color most commonly used because of its high contrast with developer on metal surfaces?
• What is the wavelength range of UVC light?
• What is a primary effect of heat on penetrant testing?
• Which of the following is not a method of applying dry developers?
• Which property relates to how well penetrant spreads over a surface?
• Which characteristic is associated with dry developers?
• How can visual acuity be increased?
• What remains after drying when applying a wet aqueous developer?
• Which company developed the visible or color contrast penetrant method?
• How can over removal of penetrant be avoided when using Type 1 penetrants?
• Most fluorescent dyes have emission peaks in which wavelength range?
• During dark adaptation, which type of vision becomes dominant?
• Which statement correctly identifies a strength of wet nonaqueous developers for inspection on accessible surfaces?
• What was the whiting made with?
• In penetrant testing, what is the purpose of applying a developer?
• Which characteristic is true for wet nonaqueous developers?
• Which type of lamps were designed to emit UVC?
• The inspector controls the intensity of the UV light and the thickness of the penetrant dye. Which of the following statements best reflects this control?
• Mercury on glass has a contact angle of about 132 degrees. What does this indicate about wetting?
• In the oil and whiting LPI method, what is the sequence used to prepare the surface?
• Most fluorescent dyes have what wavelength range?
• What brightness level must Level 3 and Level 4 penetrants maintain?
• Level 1 and Level 2 penetrants maintain what brightness percentage?
• Which industry is mentioned in relation to the oil-and-whiting LPI usage?
• Which term defines the attractive forces between molecules within a liquid?
• What is viscosity?
• Which statement is true about removing excess penetrant?
• Which penetrant type is generally best for rough surfaces such as threads or grooved parts?
• What does post-clean refer to in penetrant testing procedures?
• Which is an advantage of dry developer?
• How is the sensitivity level of fluorescent penetrant measured?
• When does dwell time begin for dry developers?
• What are typical training requirements for LPI certification?
• Which health effect is commonly associated with UVB exposure?
• What action causes penetrant removal during pre rinsing?
• Which of the following is a disadvantage of wet aqueous suspendible developer?
• What are the two kinds of vision?
• Which sequence correctly describes the general penetrant testing procedure?
• Which factors affect capillary action?
• What is absorption?
• Which statement about heat and penetrants is most accurate?
• What is visual acuity?
• Which of the following is NOT necessarily contained in all wet aqueous developers?
• What is the typical emulsification time range?
• At what temperature do fluorescent tracer dyes begin to decompose?
• How is surface tension defined?
• Which statement describes a disadvantage of using dry developer in penetrant inspection?
• What is said about aerosol penetrant removers?
• Which UV type is needed by humans for synthesis of vitamin D?
• Which option best describes a disadvantage of dry developer in relation to surface coating?
• Which term defines the attractive forces between a liquid and a solid surface?
• What is adsorption?
• What is the wavelength range of UVB light?
• Which company carried out many early LPI methods?
• What is cohesion in liquids?
• If a liquid has weak cohesive bonds, what is likely to happen on another material?
• What is hydrophilic post-emulsifiable penetrant?
• At what temperature is there almost total attenuation of fluorescent brightness?
• Which pairing has the smallest contact angle, indicating the strongest wetting: water on glass, water on copper, water on silver, or mercury on glass?
• Which statement about viscosity and penetrant performance is true?
• What is the primary purpose of UVC-emitting lamps?
• What is the contact angle?
• Which statement correctly describes fluorescence emission range?
• How is the intensity of fluorescent penetrants determined?
• Which magnifications are used to enable macro and micro indications?
• What is cone vision?
• What is Lipophilic post-emulsifiable penetrant?
• Why should aerosol penetrant removers be used with caution?
• During pre rinsing of hydrophilic penetrant, what percentage of the surface layer penetrant is removed, and by what action?
• The red dye color is chosen for its high contrast because...
• Why are dry developers not used with color contrast coatings?
• What is a general statement about post emulsifiable penetrants?
• How is wet aqueous developer applied?
• Which of the following statements is true about wet aqueous suspendible developers in terms of coating and contrast?
• UVC radiation may be produced by which process?
• Which statement correctly describes the ends of a detergent's surfactant molecule?
• What kind of penetrant can be used under ordinary shop light?
• Which property of penetrant materials is NOT listed as needing control?
• What is the minimum UV intensity required by most codes at the surface during NDT?
• Which organization certifies LPI operators in Canada?
• Which statement best describes the qualifications for LPI operators?
• Which statement correctly identifies a feature of wet aqueous soluble developers?
• What does LPI stand for?
• What is the observation of the penetrant indications very dependent on?
• The emitted energy has a longer wavelength of what?
• What are the sensitivity levels?
• What is the primary purpose of LPI?
• What is fluorescence?
• How is Lipophilic diffusion stopped?
• What is the role of corrosion inhibitors in wet aqueous developers?
• When should examination of the part begin?
• Which statement reflects an advantage of wet aqueous soluble developer?
• Which penetrant type relies on visible light for indication and is used under ordinary shop lighting?
• Which instrument is used to determine the intensity of fluorescent penetrants after preparing a thin film?
• Which statement is accurate about wet aqueous suspendible developers?
• Which of the following is NOT a described developer type?
• Why is it important to have a thin uniform coating of developer?
• Which organization manages certification of LPI operators in Canada?
• Fluorescent penetrant fluoresces under what condition?
• Which statement correctly describes wet nonaqueous developer?
• What is the purpose of using a developer with a visible penetrant?
• What are the two kinds of post-emulsifiable penetrants?
• Which step immediately follows the dwell time during the general penetrant testing procedure?
• How are WW penetrants tested for water tolerance?
• In LPI, why is color vision considered important?
• What is ultraviolet radiation?
• What is necessary during the immersion method?
• Under decreasing brightness, what happens to the contrast of indications against the background?
• Heat on penetrants may alter the rate of penetration by what primary mechanism?
• What is post-emulsifiable penetrant?
• The brightness of the fluorescent indication is affected by which factor controlled by the inspector?
• How does turning UV into visible light happen?
• Why are Lipophilic emulsifiers seldom used?
• Why do water-washable penetrants resist removal at surface openings on parts?
• What happens if traces of penetrant or developer remain on the surface after cleaning?
• If the adhesive forces are greater than the cohesive forces, what happens to a liquid on a surface?
• What is a general statement about water washable penetrants?
• Penetrants and emulsifiers should not...
• When do fluorescent dyes lose their ability to convert UV light to visible light?
• Why are Hydrophilic emulsifiers preferred?
• Which statement describes how heat affects viscosity and penetration rate?
• What are water washable penetrants a mix of?
• How are penetrants classified?
• Which city is linked with Magnaflux's early LPI work?
• Which characteristic is associated with hydrophilic emulsifiers compared to lipophilic ones?
• What is the common nickname for UVA light?
• In the development process, which statement is true?
• Under ideal conditions, how small a flaw can LPI detect?
• Why is the lipophilic post emulsifiable method becoming obsolete?
• Which of the following is a disadvantage specific to wet aqueous soluble developers?
• What is the wavelength range of UVA light?
• Which statement is NOT a stated requirement for penetrant to perform well?
• Emulsification time depends on which factors?
• What is the recommended dwell time for penetrant when not in service versus in service?
• What is adhesion in liquids and solids?
• What is the effect of over removal of penetrant on test sensitivity?
• Which description best matches the physical characteristics of dry powder used as a developer?
• The oil-and-whiting method is a form of which NDT technique?
• In longwave UV exposure for NDT, what distance is used for indirect exposure?
• What is the recommended procedure for solvent removers (Method C)?
• What is the basic function of all developers?
• Which method reduces sensitivity when applying dry developers?
• In penetrant testing, what is the recommended relationship of contact angle for effectiveness?
• Which statement about Level 3 and Level 4 penetrants' brightness is true?
• Which UV is almost never observed in nature due to atmospheric absorption?
• How much contamination can WW penetrants tolerate with no sign of gelling or separation?
• What does the thickness of wet aqueous developer coatings depend on?
• How long does the dwell time continue for Lipophilic post-emulsifiable penetrant?
• What is the preparation step for wet suspended developer before use?
• Which statement describes a benefit of wet nonaqueous developers?
• When does dwell time begin for wet non-aqueous solvent suspended developers?
• Which UV type is known for causing photochemical damage to cellular DNA due to its energy?