Pt2 Flashcards
Name a type 1 penetrant
Fluorescent penetrant
Which level of certification may be authorized to interpret and evaluate test results according to applicable standards, codes, specifications, or procedures
Level 2 and Level 3
Which nrcan document describes the process for the qualification and certification of ndt personnel in Canada
Can/CGSB- 48.9712
Which discontinuities can be found by the penetrant method
Surface cracks
It is a condition of nrcan certification that individuals abide by and sign the nrcan
Code of conduct for testing personnel
What is an advantage of liquid penetrant testing
Technicians can visually detect indications
The most common and basic of ndt methods, where examiner’s look at the surface of the part or use the aid of mirrors or cameras to aid in inspection, is called:
Visual testing (VT)
What is some of the historic methods that laid the foundation for modern penetrant testing
Oil and whiting test method
Lacquer and hammer method
Non-destructive testing is a descriptive term used for the examination of material and components in such a way that
Allows material to be examined without changing or damaging their usefulness
Name something that is not a benefit of using ndt
Measuring mechanical properties of a material
The tendency of liquids to penetrate or migrate into small openings, such as cracks, pits, or fissures, is referred to as:
Capillary action
Liquid penetrant testing can be used to examine surface breaking indications in almost any material. What is not commonly tested with penetrant testing
Wood
The________ method involves inducing a magnetic field in ferromagnetic material and then dusting the surface with iron particles
Magnetic particle (MT)
What penetrant would have the highest level of sensitivity for detecting small and tight discontinuities
Level 4
Which calibration does not need to be confirmed prior to visible liquid penetrant testing
Minimum black light intensity
What is an advantage of the liquid penetrant process
Can be used on a wide variety of metals and metal alloys
________ penetrant has a built-in emulsifier that allows the excess penetrant to be easily washed away with water spray.
Water washable
It is common for_________ developers to be applied by using an air pressured dust chamber
Dry powder
Visible penetrant examinations require suitable white light intensity at the examination surface. Common industry standards recommend a minimum light intensity greater than________
100 fc
The qualifications and certification of NDT personnel in Canada is controlled by which Canadian governing body?
Natural Resources Canada (NRCan)
Which of the following is not classified as a recommended precleaning method. Detergent cleaning, grinding, vapor degreasing, paint removers.
Grinding
The ability to spread evenly over the surface and carry into a discontinuity are desired properties during
Penetrant application
Electrostatic spraying is a technique used for applying______
Penetrant
The time during which penetrant is permitted to remain on the test specimen is considered the dwell time. Typical dwell times for small defects range from:
5 to 60 minutes
The penetrant removal process that involves wiping in the same direction with a moist cloth, is
Solvent removable
_____ developers consist of a group of chemicals that are dissolved in water and form a thin developer layer when the water is evaporated away.
Water soluble
During drying, penetrant can _____ at high temperature due to evaporation or sublimation.
Fade
The post emulsified penetrant involves water rinsing of the test specimen ______ applying the emulsifier?
Before and after
List the sequence of the solvent removable penetrant process.
Pre clean, apply penetrant, solvent wipe, apply developer, inspect, post clean
Which liquid penetrant test method would be best suited for detecting fine cracks on a relatively smooth test specimen?
Fluorescent, post emulsified
When water washing, care must be taken to not over wash penetrant from discontinuities. Water pressure should not exceed________
50 psi
What method of penetrant does not have built-in emulsifier, meaning it requires water rinsing followed by application of an emulsifier?
Post emulsified
Which penetrant process involves: pre-clean, apply penetrant, water wash, drying, apply developer, inspect, and post clean.
Water washable
_______ in a liquid is an example of cohesive force where the molecules are attracted to like molecules.
Surface tension
____________ in a liquid is an example of adhesive force where molecules are attracted to foreign matter
Wetting ability
_______ in a liquid is related to the rate at which liquid will flow under some applied stress.
Viscosity
_______ is a combination of cohesive and adhesive forces of liquid.
Capillary action
When a liquid comes into contact with a solid surface, a contact angle less than 90° results in ______ wetting.
Good
The penetrant indications that appear can be interpreted by the technician and ________ to the code or specification requirements.
Recorded, reported, evaluated
The final processing step of the liquid penetrant specimen is ________
Post cleaning
The visible light spectrum is a part of the electromagnetic spectrum that is visible to the human eye. It ranges in wavelengths from. Approximately ________
400 NM to 700 NM
Ultraviolet portion of the electromagnetic spectrum ranges from approximately ________
40 NM to 400 NM
Short exposure to ultraviolet light can cause photo keratitis and conjunctivitis, which are temporary conditions that affect the________
Humane eye
A black light works by producing _____ light, or ultraviolet light, that humans cannot see:
UVA
Uv light is not easily measurable. True or false
False
List three hazards associated with uv light
Uv exposure is not immediately felt.
Uv light emitted from uv equipment exceeds natural levels
Damage can occur with only a few seconds of exposure
Wich of the following is not an example of an eye disorder resulting from uv exposure. Flash burn, ground glass eye ball, snow blindness, cone vision
Cone vision
Ultraviolet LED lighting is being utilized to produce Ultraviolet light with out the need of ______ and ________
Filters, high power requirements
What is the desired wavelength that excites fluorescent penetrant dyes?
365 nm
Black lights with a damaged or cracked filter _________
Should never be used
What device is used to measure ultraviolet and white light intensity for liquid penetrant testing?
Radiometers
________ of the penetrant material are taken when new and stored in sealed containers where they are not subject to deterioration from heat, light, or evaporation
Control sample
What is the two-segment comparator block used for comparing different penetrant samples. Is made from?
Aluminum
A Tam panel is a chromed stainless steel test piece that provides a quick means by which a penetrant testing process can be checked for serviceability. How many starburst cracks are on the standard tam panel
5
What is the generally accepted temperature range for liquid penetrant testing?
4°c to 52°c
Deterioration of penetrants primarily results from
Aging, contamination, temperature
________ can occur during storage and use. It can affect the ability of the penetrant system. The most common one being water.
Contamination
Normal contact time for an emulsifier is _______
45 seconds
_______ involve processing a test specimen with known defects to determine if the process will reveal discontinuities of the size required.
Performance checks
Discontinuities that are related to the melting and original solidification of the molten metal, ingot, or casting, are classified as:
Inherent
Hot tears are classified as:
Casting discontinuities
Name six types of precleaning
Detergent cleaning
Solvents
Ultrasonic cleaners
Descaling solutions
Paint removers
Abrasive blasting
List the steps in a post emulsified penetrant process
Pre clean
Apply post emulsified penetrant
Water wash
Apply emulsifier
Water wash
Apply aqueous developer
Dry
Inspect
Post clean
List the four methods of excess penetrant removal
Method a: water washable
Method b: post emulsified (lipophilic)
Method c: solvent removable
Method d: post emulsified (hydrophilic)
Define wetting ability
The ability of a liquid to spread over and adhere to solid surface
Define surface tension
A condition that exits at the free surface of a body (as a liquid) by reason of intermolecular forces about the individual surface molecules and is manifested by properties resembling those of an elastic skin under tension.
Define capillary action
The tendency of liquids to penetrate or migrate into small openings, such as cracks, pits or fissures
Describe four properties of a good penetrant
Hold a dye material in suspension
The ability to carry the dye into a discontinuity open to the surface
Able to coaxed dye back up to the developed surface
The ability, when desired, to be easily removed
List the six minimum steps for the solvent removal process
1- dry wipe the surface of the part in one direction with lint free rag.
2- surface should be wiped with one pass in one direction with a rag moistened with cleaner
3- one dry pass followed by one damp pass is all that is recommended
4- additional wiping may sometimes be necessary
5- allow to dry
6- apply non aqueous developer
List five regions and ranges of the ultraviolet spectrum
Vacuum uv (40-190 nm)
Far uv (190-220 nm)
Uvc (220-290 nm)
Uvb ( 290-320 nm)
Uva (320-400 nm)
List six advantages of ultraviolet LED lighting
Reduction in maintenance costs and relamping expenses
Reducing the overall operating costs of an led equipped system overall the entire course of its life time
LEDs offer a compact size that allows them to produce intense illumination in portable packages
Longer operational life
Retain more luminosity as they reach the end of their life cycle
No need for filters or high power requirements
List the three eye disorders resulting from uv exposure.
Ground glass eye ball
Snow blindness
Welders flash
Define inherent discontinuities
Occurs when metal is molten and malleable during the casting process
Define processing discontinuities
Occurs during manufacturing process machining, extruding, rolling, welding ect
Service discontinuities
Associated with usage of the materials during its service life. Conditions such as stress, corrosion, fatigue, and erosion are caused by the everyday use of the material. It can affect mechanical, chemical properties as well as how stress is distributed throughout the material.
List six common liquid penetrant system performance checks
Light intensity check, white light
Wash temperature and pressure check
Dryer temperature check
Comparator block
Light intensity check black light
Aerosol can spray nozzle check
List six components of the human eye:
Iris
Pupil
Cornea
Lens
Retina
Optik nerve
Define photopic vision
Vision under well-lit conditions, which provides color perception.
Define scotopic vision
Monochromatic vision in very low light
Define mesopic vision
A combination of photopic vision and scotopic vision in low lighting
List eight human factors affecting quality testing
Lack of communication
Lack of resources
Complacency
Pressure
Lack of knowledge
Lack of assertiveness
Distraction
Stress
Which cgsb document governs “non-destructive testing- qualification and certification of ndt personnel” in Canada?
Cgsb 48.9712
Define false indications
Penetrant indications that occur on the surface of the test specimen due to improper processing or contamination
Define relevant indications
Penetrant indications on the surface of the specimen that are caused by a discontinuity
Define non-relevant indications
Penetrant indications that are true indications that are present by design and are in no way detrimental to the usefulness of the test specimen
Define acceptance criteria
Specified indicators or measures employed in assessing the ability of a component, structure, or system to perform its intended function.
List ten items that should be recorded on a pt test report
Liquid penetrant type (visible or fluorescent)
Examination personnel identity and qualification level
Results of Examination, identifying type, size, and location of defects
Material and thickness
Lighting equipment
Identification of object being examined
Acceptance standard code
Equipment used and method of inspection
Pre-cleaning details, if applications
Report number, client and job number, date and time
What are the different ways of applying dry developer?
Soft brush, powder gun, hand powder bulb, or by other means as long as the powder is dusted evenly over the entire surface being examined.
How long shall an examiner be in a darkened area prior to performing an inspection with a black light?
The examiner should be in a darkened room five minutes prior to performing an examination with black light
What are the allowables for part temperature during an LPI inspection?
Should not be below 40°F (5°c) nor above 125°F (52°C)
When would a revised procedure be required?
A change of requirement in an essential variable shall require requalification of the written procedure
What are the typical discontinuities that can be found using LPI
Lamination
Cold shuts
Porosity
Laps
Cracks
Seams
List the typical cleaning agents that may be used in LPI inspections?
Paint removers
Detergents
Descaling solution
Organic solvents
If not practical to conduct an LPI examination within the allowable temperature range, what must be done
Examination procedure requires qualification. At the proposed lower or higher temperature ranges of the penetrant materials and processing
Can water washable penetrants be retested
A retest with a water washable penetrant may cause a loss of marginal indications due to contamination
What are the restrictions to removing solvent penetrant upon completion of the dwell time?
Some of the restrictions of removing solvent penetrant include flushing the surface with solvent, following the application of the penetrant, and prior to developing
What is the time required for hydrophilic emulsification?
Shall not be more than two minutes unless a longer time is qualified for a specific part
