MT GINZEL BRO 151-300 Flashcards
- When A.C. is used instead of D.C. for a head shot on a steel tube, the field
on the inside surface of the tube is
A. much less
B. much more
C. nearly the same
D. both are exactly zero
D. both are exactly zero
152.The best way to determine magnetizing current required for irregularly shaped
pieces is
A. length to diameter ratio equations
B. 40 amps per mm of part thickness
C. empirically (trial and error)
D. finite element analysis
C. empirically (trial and error)
- When using the prod method of MPI, defects are normally looked for
A. between the prods
B. under the prods
C. in circles about 4” (100mm) radius from the prods
D. in all of the above locations
A. between the prods
- In order to maintain the same field strength at the midpoint of prods spaced 8
inches apart as was had with a 6 inch spacing you must
A. increase the magnetizing current
B. decrease the magnetizing current
C. use D.C. instead of A.C.
D. use larger diameter prod electrodes
A. increase the magnetizing current
- Which is not a consideration when choosing current type to use for prod
inspection methods of MPI?
A. particle mobility
B. safety
C. power consumption
D. heating effects on equipment
B. safety
- Capacitive discharge methods of producing a magnetizing current do so for only
a short duration.
A. typically 1 to 2 seconds
B. typically 0.5 to 1 seconds
C. typically 10 to 100ms
D. typically 5 to 55 µs
C. typically 10 to 100ms
- Precracked magnetic steel plates are an effective means of
A. qualitative analysis of MPI bath concentrations
B. quantitative analysis of MPI bath concentrations
C. calibrating ammeters on MPI bench units
D. sizing unknown MPI indications
A. qualitative analysis of MPI bath concentrations
- Typical pocket sized magnetic field indicators are used to measure
A. magnetizing force in a coil
B. external residual fields
C. internal residual fields
D. circular field strength during current flow
B. external residual fields
- A low cost rugged tool used to measure residual magnetic field strength of
ferromagnetic parts is a
A. residu-meter
B. shunt meter
C. magnetic field indicator
D. Helmholtz coil
C. magnetic field indicator
- A good magnetic field indicator (MFI) should have which characteristic?
A. rugged supports to prevent damage to the pointer needle
B. not be easily demagnetized by strong external fields
C. not induce magnetic poles of the parts they test
D. all of the above
D. all of the above
- Excessive background in wet fluorescent MPI testing results from
A. excessive current density
B. excessive particle density
C. excessive blacklight intensity
D. both a and b
D. both a and b
- The standard steel ring 7/8” thick having a 1 1/4” diameter central hole and
twelve 0.007” diameter holes arranged with increasing depth from the outside
edge of the ring is called a(n)
A. annular ring
B. Ketos ring
C. ASME ring
D. DIN ring
B. Ketos ring
- Probability of seeing a wet fluorescent MPI indication
A. increases with increasing blacklight intensity
B. increases with decreasing white light background
C. increases with decreasing blacklight intensity
D. both a and b
D. both a and b
- Although settling time prior to measuring wet fluorescent magnetic particle
concentration is now increased to 1 hour for most standards, complete settling
usually takes
A. 15 minutes
B. 30 minutes
C. 2 hours
D. 24 hours
D. 24 hours
- When viewing the oil carrier of wet fluorescent particles (ie. the liquid
without the particles) under blacklight it usually has a _________ tint.
A. yellowish
B. bluish
C. yellow/green
D. reddish
B. bluish
- The purpose of adding an antifoaming agent to wet MPI bath is to
A. reduce suds resulting from agitation
B. eliminate phosphates for environmental protection
C. prevent fluorescent material from disbonding from the oxides
D. all of the above
A. reduce suds resulting from agitation
- Indications from medium to deep surface breaking seams found using A.C. MPI
A. are not possible to find
B. usually look alike
C. require extra large particles
D. form double indications
B. usually look alike
- Fastest particle settlement in an MPI bath would occur for
A. small dense particles in a low viscosity liquid
B. small dense particles in a high viscosity liquid
C. larger dense particles in a low viscosity liquid
D. all of the above would settle about the same rate due to the Bernoulli
effect
C. larger dense particles in a low viscosity liquid
- MPI indication width tends to increase for increasing
A. defect width
B. defect depth
C. magnetizing current strength
D. all of the above
D. all of the above
- Because in general, there exists a direct relationship between indication
width and seam (defect) depth, a minimum magnetizing current level can be set
to
A. maintain uniform indication widths
B. detect significant flaws
C. both a and b
D. none of the above
B. detect significant flaws