NDI MAG PARTICAL

Start Studying!

Terms

undefined, object

copy deck

Magnetism?: The ability of matter to attract matter to itself.
Magnetiization?: The process by which elementary magnetic domains of a material are alighned predominantly in one direction.
magnetic domains?: Materials that can be magnetized possess atoms that group into submicroscopic regions.
Un-magnetized domains are aligned how?: They are randomly oriantated.
Magnetized domains are aligned how?: The are align themselves parallel with the magnetic field.
poles are attacted to earths magnetic pole and are therefore called?: North and south pole.
Objects are magnetized when part or all of its molecules are what?: Aligned
This quality of having two opposite magnetic poles is called?: Polarity
A conceptual representation of magnet flux that can be illustrated vy the line pattern produced when iron fillings are sprinkled on paper laid over a permanent magnet?: Mangetic lines of force.
The strength of the magnetic field is?: field intensity
represents the level of magnetism or?: flux density
flux lines are proportional to the what?: amount of magnetism in parts
What seeks a new path around surface cracks due to high reluctance of air?: magnetic flux lines
when a magnetic field is inturupted by a discontinuity?: leakage field
the stronger the leakage field the what?: The closer the discontinuity is to the surface.
magnetic fields must be in a faborable direction with respect to a discontinuity to produce an indication. This is called what?: effects of flux direction
Best results for inspecting discontinuities are optained when?: flux lines are perpendicular to it.
when magnetic field has little or no effect on the material?: Diamagnetic
when magnetic field has some effects on the material?: paramagnetic
when magnetic field has great effect on the material?: ferromagnetic
what procedure do you clamp the part between the contact plates to induce circular field?: circular magnetism1
what is used for hollow parts?: Central conductor bar
Why do you do circular magnitization first?: because you can not verify magnetization or demag
when parts are placed in a coil you are doing what?: longitudinal magnetization
In lognitudinal magnetization poles run?: South to north inside the part.
what kinds of magnets have longitudinal fields?: BAR
ease of a magnet to be magnetized is know as?: permeability
ease of magnetization indicates?: high permability
difficulty of magnetization indicates?: low permability
Property of a metal to retain magnetic FIELD after the magnetizing force has been removed.: retentivity
metals with strong magnetic fields have high?: retentivity
Low retentivity means what?: the part loses most of its magnetizim
magnetism remaining after a magnetic force has been removed?: residual magnetism
chemical properties and size and shape of the material determine what?: The amount of residual magnetization.
what is reluctance?: The resistance of a material to establishment of magnetic flux.
negitive or revers magnetizing force used to reduce magnetic field?: coercive force
If magnetic force is reversed and gradually removed what will happen?: magnetism will diminish.
What is electrical current used for?: is use to induce or creat magnetic fields in parts.
what type of current as a single phase or multipule phase?: A/C
what type of currentis used for surface detections?: A/C
DC is the bes sourced of?: Best sorce of rectified A/C
If you are doing 100% inspection what type of current will you use?: D/C
When an electrical current is passed through a conductor what happens?: a magnetic field is formed arount the conductor.
Amount of electrical current determines the amount of what?: amount of strength it will have
the stength in a coil conductor is determined by?: The amount of loops
The H-710G Is?: Horizontal stationary inspection unit.
H-710G uses what type of partical application?: Wet partical only!
KCH-3D IS WHAT?: a MOBILE UNIT
What type of partical application does the KCH-3d use?: Wet or dry
What are the duty cylces for a KCH-3d?: 0-600 amps continous use

600-1200 amps 3 min on-5min off

1200-2000- 1 min on 5 min off

2000-3000- 1 min on 10 min off
These are all for AC
DC output duty cycles for KCH-3D?: 0-1250- continous

1250-2000- 1 min on 5 min off

2000-3000- 1 min on 10 min off
DA-200(parker probe) and the TTU-432/E are used and transported how?: Used on ship or shore and are hand carried.
The DA-200 and the TTU432E use what type of partical applicaltion?: Wet or dry
The DA-200 and the TU432E are powered by?: single phase HWRAC
The DA-200 and the TTU432E use what type of current for Demag?: AC withdraw for both

AC decay for the TTU432E
DA-200 is what type of device?: Yoke type that only provided logitudinal.
How due you apply dry particals?: by hand with a rubber squeeze bulb or plastic squeeze bottle.
How do you apply wet particals?: bath or aerosol
What is the residual method of application for particals?: apply power, stop power, apply bath, stop bath
apply bath, apply power, stop bath, stop power is what type of method.: continous which is the most common.
what is the amps for a uniform and cylindrical in shape?: 300-800 normally 500
low permeability alloys or inclusions amps would be?: 800
the greatest two distances on the outside of the part are?: the distance.
What formula do you use to find the wall thickness?: (cbc)+2(wt)=D
what formula do you use to get your head shot?: Diameter x type steel.
what formula do you use to determain the number of turn?: c
-----
4(CBC)
How do you determain your circumfrence for your CBC turns formula?: ID X pie
Why is it critical to determain the cross sectional area of a part compared to the cross sectional area of the coil?: So that you know if the part goes on the bottom or centered in the coil.
What is the formula to find the area of the coil?: A=pie X Rsq
for the area of a rectangle or square part you would use what formula?: A=H X W
If the cross sectional are of the part is less than 10% of the coil area where does your part go: bottom of the coil.
when your parts cross sectional area is greater then the area of the coil your part goes?: centered in the coil
What formula do you use to find the affective diameter of a hollow part?: draw it!
Length to diameter ratio as to be greater than or less than what.: Greater than 2in or less then 15in if its over you use 15 if its under you use extension.
magnetizing fields extend how far from the center of the part?: 6-9 inches
why is it critical to determine the relationship between the cross sectional area of the part and the cross sectional area of the coil?: So that you know where to put your part inside the coil?
to find the area of the coil and the part what formula would you use or circuar areas?: draw it/say it.
To find the area of a square what formula do you use?: draw it or say it
for the part to be on the bottom the cross sectional area of the part has to be less than what: 10%
What formula would you use to find the effective diameter of a circle and a square?: draw it
(L/D) determines what?: The effective are of the field distance.
Your length to diameter as to be in between a ratio of what. If its over or under what do you do?: Between 2-15 in. Over you use 15 and under you use extensions.
the useful magnetizing field extends how far in the coils?: 6-9in for the center line each way
How much over lap do you need for if your part is 60 inches and how many times would you shot it?: Its to big you would have to do a cable wrap.
What is the formula for a part lying in bottom of coil?: draw it
whatis the formula for centering a part in the coil?: draw it
what is the formula for cable wrap?: draw it?
What is the purpose of demagnetization?: to reduce the magnetic field retained in the part.
Aircraft ferromagnetic parts are demaged when?: part is installed on a/c
part needs further machining
welding is involved
ball bearings or gear teeth
effects coating
prevents proper cleaning
mangetic fields do what continously>: reversing and decreasing at the same time
decreased magnetism is accomplished by?: smaller and smaller hystersis loops created by decreasing currnet.
The smaller the hysteresis loop produced the more what?: Demag that has been accomplished.
what type of dmag is more comvienent but does not penetrate very deep below the surface?: AC
What kind of demage works well on larg parts?: AC step down. and AC decay
AC coil withdraw is more suitable for what?: Small parts and larg numbers of parts.
What type of dmag is the most complete and affective?: DC Multi point reversing step down
when dmaging you want to get the residual to what?: the lowest posible level.
a part is considered to be satisfactorily demaged when its mag field is at or be low how many gauss meter or below what for the feild indicator?: 3 and 2
what is the most accurate way to messure residual magnetism?: Field indcator
when do you have to have your part lying east to west for mesuring residual?: when you use a compass indicator.
What are the six things you need to learn about a part when you recive it?: alloy, shape, size, surface condition, permability, and retentivity
what type of partical insures a complete coverage, partical mobility, and indicates tight defects?: WET
Wet partical charachteristics?: globular/round

.0002-.006 in

color
what collor is visible particals?: Black or red
what is the only authorized partical type for A/C?: Wet flourecent
what type of partical is considered superior in detecting subsurface discontinuities but lacks mobility and are harder to apply?: DRY
dry partical charachteristics?: elongated rod shaped

.002-.006 in

gray, black, red, or yellow
what are the two different directions of magnetic fields?: longitudinal or circular
When using a mag bench what do you stand on?: isulating floor matting rated for the voltage of equipment
what is the Need for process control?: MAG partical is not a fail safe method.
what are two reasons flaws can be present and not indicated?: substandard material or equipment and process diviation
What is the primary reason for material degradation>: contamination
What are the 5 things that cause material degradation>: water, organic coatings, organic solvants, dirt, soil , other insoluble materials, and acid an alkelines.
At what temp does heat degradation cause flourecents to go bad and what temp destroys them?: 140 and 250 degrees F
material contamination, equipment malfuction, and procedure diviation are what?: Directly porportional to the no of parts inspected.
why are minimul test schedules set?: Due to the lake of uniformity of work load.
new material needs to be what be for put into service?: tested
You perform a petroleum based vehicle contamination check prior to what?: mixing inspection bath
petroleum based vehicles have to sit for how long before performing a check?: 1 hour in original container
how do you inspect for flourecents you your petroleum?: with a black light
How do you perform a bath contamination check?: using a cetrifuge tube
partical contamination about recommended levels could cause what?: excessive background indications and below limits may miss defects.
what do you have to test daily and after 8 hrs of continuous use.: your bath
when using the centifuge tube how do you messure fluorecent consentration and the visible particle concentration: .1-.4 for fluorecent

1.2-2.4 for visible
petroleum based contamination check is performed when?: prior to each use at least once each day.
examain fluid in centrifuge tube it should not do what?: should not fluorece
pet contamination should not exceed what?: 30% of bath concetrate
background fluor check should be performed when?: Prior to each use and after every 8 hrs of countinious use.
what tool is used to check stationary voltage?: keto tool
how often do you check AC/DC on a stationary unit?: every seven days
perform amperage inticator accuracy check when?: Every six months
perform quick break check every?: 60 days
what is a quck break check for?: checks rapid colaps of magnetic field

tested at 2000 amps for .5 sec.
ded weight lift check is done?: every 30days
dead lift check is performed on what?: electromagnetic yokes DA-200
interpretation: determination of what causes and indication
surface indications are usually?: well defined build up of particals
subsurface defects are indications are usually: broad and fuzzy
Surface discontinuites are more harmfull then?: subsurface
Sharp discontinuies such as fatigue cracks and grinding cracks are more harmful then: rounded discontunities
discontinuities weather surface or subsurface that lies at a right angle to applied stress is more likely to be harmful then?: one that lies parallel to applied stress.
Classify deffect indications?: A-positive defect
B-questionable
C-No defect
SD-surface defect
what is an extension of the magnetic particle inspection method used for detecting flaws in problem areas?: mag rubber inspection
What is manetic rubber inspection used for?: areas with limited visual accessability.

coted surfaces

complex shapes and edges
MRI procedures?: obtain material, clean area, remove surface inperfections, form resevior dam.
MRI mixing and measuring?: must be mixed good with no streaks or color variation.

messure one gram runbber bas equals on cubic centimeter base material
Perferred magnetizaion method for MRI?: DC portables.

May also use mobile or stationary.

stationary has limited use.
Defect to field orientation. when using portable equip?: Pour mixed materials
mag in one direction
wait 60 sec
rotate probe 90 degrees and remag

allow to cure.
what do use use to examine MRI indications: 7x - 10x illuminated magnifing glass.
Interpretation?: Determination of what causes a indication.
Surface indications?: Well defined build up of particals.
Subsurface indications?: Usually broad and fuzzy
Surface discontinuities are more harmful than?: Subsurface.
You should perform and amerage indicator accuracy check how often?: at least once every 6 mon.

Check for proper output
Quick break check is performed when?: Every 60 days.

Check for rapid collaps of magnetic field.

Check using 2000 amps for .5 sec.
Dead weight lift check is performed on what unit?: DA-200 parker probe.
Dead weight lift check is performed how often?: Every 30 days

Checks for proper AC and DC
What are the inspection procedures for Dead weight check For AC and DC?: For AC space legs of yoke two to four inches aprt place 10 lbs weight and lift weight with unit engaged.

For DC Use 30 lbs weight.

for 40-50 lbs test spread legs 4-6 inches apart.
magnetic partical inspection includes exposure to?: oil, pastes, and electrical current.
Flaws can be present and not indicated for a number of reasons name two?: Substandard materials either new or through service degradation or process diviation in equipment procedures or condition.
New material must what before use?: tested
petroleum based vehicle check done when?: prior to mixing inspection bath.
before performing pet base vehicle check it must sit for how long?: 1 hour
in use bath concentration camp?: used to insure proper particle to bath ratio.
Bath concentration check is done when?: Performed daily and after 8 hours of consecutive use

Flourecent particals should be .1-.4 and 1.2-2.4 for visible particals
pet based contamination check is performed when?: Prior to use at least once a day.

Contamination will not fluorece.

Contamination shall not exceed 30%
background flourecenet checkshall be performed when?: Prior to each day and after every 8 hours of continous use.
arosal cans should be checked for?: performance and residual magnetism propr to each use and demaged if necessary
Mobility checks are performed.: On dry powder materials at least once a day prior to use.

Or every seven days.
System effectiveness check is done?: At least every seven days with ketos tool stell ring inspection

It is used to verify aperage.
For system effectivness you can see how many indications on AC and DC: AC-1000 1 line

DC- 1400 3 holes, 2500-5 holes, and 3400-6 holes.

Start Studying!

Deck Info

Number of cards 171