mpi training [compatibility mode]

5/22/2018 MPI Training [Compatibility Mode]

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TrainingTrainingMagnetic Particle InspectionMagnetic Particle InspectionEquipments & AccessoriesEquipments & Accessories

CalibrationCalibration


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IntroductionIntroduction

This session aims to educate all of you aboutThis session aims to educate all of you aboutequipments and the quality control needed forequipments and the quality control needed forthe equipment and the necessary processes.the equipment and the necessary processes.

We will be going through:We will be going through: MachinesMachines

AccessoriesAccessories

CalibrationCalibration


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AgendaAgenda

Portable type.Portable type. Mobile type.Mobile type. Stationary Type.Stationary Type. Automatic Type.Automatic Type. Black Light type.Black Light type.

LightLight sensitive instruments.sensitive instruments. Malfunctioning of equipments.Malfunctioning of equipments. Calibration of equipment.Calibration of equipment.


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Portable MachinesPortable Machines

Permanent Yoke

Electro-Magnetic Yoke

Prod type 750 to 1000 ampere


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Reasons for Portable MachinesReasons for Portable Machines

Portability (Light weight & Easy to carry )Portability (Light weight & Easy to carry )

Power not available.Power not available.

Large Components to be tested.Large Components to be tested.

On site work.On site work.


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YokesYokes

Permanent Magnetic yoke.Permanent Magnetic yoke.

When no power is available and advantage to be used where no voltage to beWhen no power is available and advantage to be used where no voltage to beused. Explosive areas. (Safety question.)used. Explosive areas. (Safety question.)

ElectroElectro--magnetic yoke Available both in AC / DC outputmagnetic yoke Available both in AC /DC output

Battery operated also used nowBattery operated also used now-- days. Used where no power is available.days. Used where no power is available.

The field can be regulated.The field can be regulated.

They have articulated legs that can be adjusted as per the test location.They have articulated legs that can be adjusted as per the test location. Main advantage light weight.Main advantage light weight.

Can be used on finished products without causing arc burns.Can be used on finished products without causing arc burns.

The yokes can be also used for demagnetizing components by ACThe yokes can be also used for demagnetizing components by ACmagnetizing field.magnetizing field.


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Portable Prod typePortable Prod type

Prod type equipments pass the current through the component throughProd type equipments pass the current through the component through

prods.prods. They are more sensitive to detect subThey are more sensitive to detect sub--surface defects compared to yokes.surface defects compared to yokes.

They produce both AC & HWDC magnetizing current.They produce both AC & HWDC magnetizing current.

They are limited to maximum output current from 750 amperes to 1500They are limited to maximum output current from 750 amperes to 1500amperes.amperes.

They weigh between 20 kilos to 40 kilos.They weigh between 20 kilos to 40 kilos. The shorter the secondary cables the better the output and lighter theThe shorter the secondary cables the better the output and lighter the

equipment.equipment.

The equipment can be also used as a demagnetizer in the AC mode.The equipment can be also used as a demagnetizer in the AC mode.

The prods to be kept clean to avoid arc burns.The prods to be kept clean to avoid arc burns.

Precaution to be taken to be used on finished component (they can used withPrecaution to be taken to be used on finished component (they can used withcopper braided tips or lead tips), it is better to be avoided if alternate option iscopper braided tips or lead tips), it is better to be avoided if alternate option isavailable.available.

The portable units along with cables can be also for coil magnetizations, byThe portable units along with cables can be also for coil magnetizations, bywrapping the cables around the component.wrapping the cables around the component.


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Mobile Type MachinesMobile Type Machines


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Reasons for Mobile MachinesReasons for Mobile Machines

MobilityMobility

Can produce large amount of Current.Can produce large amount of Current.

Capable of Demagnetization Circuits.Capable of Demagnetization Circuits.


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Mobile UnitsMobile Units They are similar to prod portable unit.They are similar to prod portable unit.

Mobile units can produce current from 2000 amperes to 8000 amperes.Mobile units can produce current from 2000 amperes to 8000 amperes.

They are also used as a power pack for stationary equipments.They are also used as a power pack for stationary equipments.

They can produce AC/ HWDC/ FWDC currents.They can produce AC/ HWDC/ FWDC currents.

They are mostly used where large current is required for massive components.They are mostly used where large current is required for massive components.

for cable wrapping technique.for cable wrapping technique.

Sometime the components cannot be moved so long cables are used for theSometime the components cannot be moved so long cables are used for therequired output or to test at high altitudes.required output or to test at high altitudes.

Cables as long as 40 meters are used sometimes.Cables as long as 40 meters are used sometimes.

This units can also have inThis units can also have in-- built demagnetization facilities.built demagnetization facilities.

The only disadvantage they need high input current.The only disadvantage they need high input current.


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Stationary Machines.Stationary Machines.


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Stationary MachinesStationary Machines Bench or stationary units are generally used for high volume production .Bench or stationary units are generally used for high volume production .

They are mostly designed as wet method inspection units.They are mostly designed as wet method inspection units.

They are available in two models Current & coil Series, Current & YokeThey are available in two models Current & coil Series, Current & Yokeseries.series.

They produce AC/HWDC/FWDC & 3 FWDC.They produce AC/HWDC/FWDC & 3 FWDC.

These machine produce both circular & longitudinal magnetization.These machine produce both circular & longitudinal magnetization.

Care should be taken for setting the current in MultiCare should be taken for setting the current in Multi-- Directional units sinceDirectional units since

they produce both fields.they produce both fields. These units in some cases have inThese units in some cases have in-- built demagnetization facility.built demagnetization facility.

These units come with automatic loading, magnetization, spraying, andThese units come with automatic loading, magnetization, spraying, andautomatic unloading.automatic unloading.

The output current used in this product ranges from 1000 to 20000 amperes.The output current used in this product ranges from 1000 to 20000 amperes.

These machine usually have a head stock & movable tail stock.These machine usually have a head stock & movable tail stock. Usually they have one coil, for longitudinal magnetization.Usually they have one coil, for longitudinal magnetization.

The coils used in these machine are standard 5 turn coil or as per customersThe coils used in these machine are standard 5 turn coil or as per customersrequirement.requirement.

The sizes of the coils also vary from 6 inches to 36 inches.The sizes of the coils also vary from 6 inches to 36 inches.


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Test BenchTest Bench Some have separate demagnetizers for faster production output.Some have separate demagnetizers for faster production output.

The test benches also vary in sizes from 450mm bed length between heads toThe test benches also vary in sizes from 450mm bed length between heads to5000mm.5000mm.

In many automated systems the headstock have rotating heads for theIn many automated systems the headstock have rotating heads for therotation of the components at the time of inspection.rotation of the components at the time of inspection.

The Black light also moves along with the inspector in automated systems forThe Black light also moves along with the inspector in automated systems foreasy inspections.easy inspections.

The latest machines have feedback system.The latest machines have feedback system.

They also come with retention facility and digital ammeter.They also come with retention facility and digital ammeter.

In some particular cases the complete visual system eliminates the man forIn some particular cases the complete visual system eliminates the man forinspection.inspection.

Special machine with multiple contact heads (multi direction)are used toSpecial machine with multiple contact heads (multi direction)are used to

magnetize the component so that time can be saved.magnetize the component so that time can be saved. These machine have rotation base for inspection.These machine have rotation base for inspection.


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Automatic MachinesAutomatic Machines

NutsNuts

Billets.Billets.

Bars.Bars.

Similar component with sameSimilar component with samemeasurements.measurements.

Crankshaft.Crankshaft.

Camshaft.Camshaft.

Other similar componentsOther similar components


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Conveyor systemsConveyor systems


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Multi directional MagnetizationMulti directional Magnetization


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Special Equipment for special largeSpecial Equipment for special largecomponents.components.


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Machine with visual inspection systemMachine with visual inspection system


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Future Magnetic Crack DetectorsFuture Magnetic Crack Detectors

Automatic Feeding.Automatic Feeding.Automatic sprayingAutomatic spraying

Automatic Current application.Automatic Current application.

Set Current values will be the output irrespectiveSet Current values will be the output irrespectiveof the impedance.of the impedance.

Automatic Program controlled current selectionAutomatic Program controlled current selectionfor various parts.for various parts.

Automatic Segregation with marking system.Automatic Segregation with marking system.

Digital printout with recording facilities.Digital printout with recording facilities.


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Introduction to Demagnetization.Introduction to Demagnetization.

All ferromagnetic materials, after having beenAll ferromagnetic materials, after having beenmagnetized, will retain a residual magnetic field tomagnetized, will retain a residual magnetic field to

some degree. This field may be negligible insome degree. This field may be negligible inmagnetically soft materials, but in hard metals itmagnetically soft materials, but in hard metals itmay be comparable to intense fields associatedmay be comparable to intense fields associatedwith the special alloys used for permanentwith the special alloys used for permanentmagnets.magnets.

It is not always necessary to demagnetize partsIt is not always necessary to demagnetize partsafter magneticafter magnetic--particle inspection. However,particle inspection. However,although demagnetization involves time andalthough demagnetization involves time andexpense, it is essential in many instances.expense, it is essential in many instances.Demagnetization may be easy or difficult,Demagnetization may be easy or difficult,depending upon the type of metal. Metals withdepending upon the type of metal. Metals withhave high coercive forces are most difficult tohave high coercive forces are most difficult todemagnetize. High retentivity is not necessarilydemagnetize. High retentivity is not necessarilyrelated directly to high coercive force, so that therelated directly to high coercive force, so that thestrength of the retained magnetic field is notstrength of the retained magnetic field is notalways an accurate indicator of the ease ofalways an accurate indicator of the ease ofdemagnetizing.demagnetizing.

It is better to keep the demagnetizer coil openingIt is better to keep the demagnetizer coil openingfacing Eastfacing East West.West.

Reasons for Demagnetizing.Reasons for Demagnetizing.

There are many reasons for demagnetizing the part afterThere are many reasons for demagnetizing the part aftermagneticmagnetic--particle inspection (or, for that matter, afterparticle inspection (or, for that matter, aftermagnetization for any reason). Demagnetization ismagnetization for any reason). Demagnetization isnecessary if:necessary if:

The part will be used in an area where residual magneticThe part will be used in an area where residual magneticfield will interfere with the operation of instruments thatfield will interfere with the operation of instruments thatare sensitive to magnetic field or may affect the accuracy ofare sensitive to magnetic field or may affect the accuracy ofinstruments incorporated in assembly that containsinstruments incorporated in assembly that containsmagnetized parts.magnetized parts.

During subsequent machining, chips may adhere to theDuring subsequent machining, chips may adhere to thesurface being machined and adversely affect surface finish,surface being machined and adversely affect surface finish,dimensional and tool life.dimensional and tool life.

During cleaning operations, chips may adhere to theDuring cleaning operations, chips may adhere to thesurface and interfere with subsequent operation such assurface and interfere with subsequent operation such aspainting or plating.painting or plating.

Abrasive particle may be attracted to the magnetized partAbrasive particle may be attracted to the magnetized partsuch as bearing surfaces, bearing raceways, or gear teeth,such as bearing surfaces, bearing raceways, or gear teeth,resulting in abrasion or galling, or may obstruct oil holesresulting in abrasion or galling, or may obstruct oil holesand grooves.and grooves.

During some electric arcDuring some electric arc--welding operations, strongwelding operations, strongresidual magnetic fields may deflect the arc away from theresidual magnetic fields may deflect the arc away from thepoint at which it should be applied.point at which it should be applied.

A residual magnetic field in a part may interfere with reA residual magnetic field in a part may interfere with re--

magnetization of the parts at a field intensely too low tomagnetization of the parts at a field intensely too low toover come the remanent fields in the part.over come the remanent fields in the part.

It is also frequently required when parts, after use ofIt is also frequently required when parts, after use ofmagnetic chucks or lifting magnets.magnetic chucks or lifting magnets.


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Different Methods of Demagnetization.Different Methods of Demagnetization.

AC Current Decay method.AC Current Decay method.

Reducing the field method.Reducing the field method.

DC reversal technique.DC reversal technique.

AC yoke.AC yoke.


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DemagnetizersDemagnetizers


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AccessoriesAccessories


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Future UV source.Future UV source.

LED Lights.LED Lights.

Light weight.Light weight.

Easy to carry.Easy to carry.

Available in both AC & Battery operated.Available in both AC & Battery operated.

Very High intensity upto 20,000 micro watts.Very High intensity upto 20,000 micro watts.

Life 20,000 average hours.Life 20,000 average hours.


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Magnetic Crack Detector check points.Magnetic Crack Detector check points.

Electrical System ChecksElectrical System Checks Changes in the performance of the electrical system of a magnetic particle inspectionChanges in the performance of the electrical system of a magnetic particle inspection

unit can obviously have an effect on the sensitivity of an inspection. Therefore, theunit can obviously have an effect on the sensitivity of an inspection. Therefore, theelectrical system must be checked when the equipment is new, when a malfunction iselectrical system must be checked when the equipment is new, when a malfunction issuspected, or every six months. Listed below are the verification tests required bysuspected, or every six months. Listed below are the verification tests required by

ASTM EASTM E--1444.1444. Maximum Unit OutputMaximum Unit Output

A magnetic particle unit should be checked regularly (daily) to verify that theA magnetic particle unit should be checked regularly (daily) to verify that themaximum current output of its electrical system has not changed over time. This checkmaximum current output of its electrical system has not changed over time. This checkis performed by placing a large diameter (typically 1 inch or more) copper or aluminumis performed by placing a large diameter (typically 1 inch or more) copper or aluminum

bar between the contacts and energizing the circuit with the current control set to thebar between the contacts and energizing the circuit with the current control set to themaximum value. The maximum amperage as recorded by the system's ammeter shouldmaximum value. The maximum amperage as recorded by the system's ammeter shouldbe noted and compared to the value obtained when the unit was last certified orbe noted and compared to the value obtained when the unit was last certified orcalibrated. A significant drop or gradual decay indicates a problem with the unit thatcalibrated. A significant drop or gradual decay indicates a problem with the unit thatshould be corrected.should be corrected.

Internal Short TestInternal Short TestThe internal short circuit testing is required to determine the if current is "leaking past"The internal short circuit testing is required to determine the if current is "leaking past"the test article. Internal electrical leakage will cause the test equipment to indicatethe test article. Internal electrical leakage will cause the test equipment to indicate

current is flowing through the component when it is actually bypassing thecurrent is flowing through the component when it is actually bypassing thecomponent. The process for checking equipment for this condition is to energize thecomponent. The process for checking equipment for this condition is to energize thesystem with nothing between the contact heads and the amperage set to the highestsystem with nothing between the contact heads and the amperage set to the highestoutput. If the ammeter shows any current flow, internal shorting should be suspected.output. If the ammeter shows any current flow, internal shorting should be suspected.


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Calibration of the MachineCalibration of the Machine

Ammeter CheckAmmeter CheckIt is important that the ammeter provide consistent and correct readings. If the meter is readingIt is important that the ammeter provide consistent and correct readings. If the meter is readinglow, over magnetization will occur and possibly result in excessive background fluorescence. Iflow, over magnetization will occur and possibly result in excessive background fluorescence. Ifammeter readings are high, flux density could be too low to produce detectable indications. Toammeter readings are high, flux density could be too low to produce detectable indications. Toverify ammeter accuracy, a calibrated ammeter is connected in series with the output circuit andverify ammeter accuracy, a calibrated ammeter is connected in series with the output circuit andvalues are compared to the equipment's ammeter values. Readings are taken at three output levelsvalues are compared to the equipment's ammeter values. Readings are taken at three output levelsin the working range. The equipment meter is not to deviate from the calibrated ammeter morein the working range. The equipment meter is not to deviate from the calibrated ammeter morethan +/than +/ -- 10 percent or 50 amperes, whichever is greater. If the meter is found to be outside this10 percent or 50 amperes, whichever is greater. If the meter is found to be outside thisrange, the condition must be corrected. It should be noted that when measuring halfrange, the condition must be corrected. It should be noted that when measuring half--wavewaverectified current, the readings should be doubled.rectified current, the readings should be doubled.

Quick Break TestQuick Break Test

A quick break circuit is primarily used in threeA quick break circuit is primarily used in three--phase, fullphase, full--wave rectified systems to ensurewave rectified systems to ensurelongitudinal magnetic fields maintain their strength to the end of a component. Quick breaklongitudinal magnetic fields maintain their strength to the end of a component. Quick breakcircuits cause the current to abruptly collapse or drop to zero at the end of the activation cycle. Bycircuits cause the current to abruptly collapse or drop to zero at the end of the activation cycle. Bydoing this, low frequency eddy currents are produced close to the surface of a component. Thesedoing this, low frequency eddy currents are produced close to the surface of a component. Theseeddy currents help extend the useable longitudinal field to the ends of the component. Toeddy currents help extend the useable longitudinal field to the ends of the component. Todetermine if a quick break system is functioning properly, an oscilloscope is often used. Bydetermine if a quick break system is functioning properly, an oscilloscope is often used. Byobserving the sine wave of the current, it can be determined if current drops abruptly when theobserving the sine wave of the current, it can be determined if current drops abruptly when thecircuit is interrupted.circuit is interrupted.

Shot Timer CheckShot Timer Check

When a timer is used to control the shot duration, the timer must be calibrated. ASTM EWhen a timer is used to control the shot duration, the timer must be calibrated. ASTM E--14441444 --01 requires the timer be calibrated to within +/01 requires the timer be calibrated to within +/-- 0.1 second. A certified timer should be used to0.1 second. A certified timer should be used toverify the equipment timer is within the required tolerances.verify the equipment timer is within the required tolerances.

Yoke calibration is done by dead weight . AC 4.5 Kilo. DC 18.1 kilo.Yoke calibration is done by dead weight . AC 4.5 Kilo. DC 18.1 kilo.


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LightingLighting

Magnetic particle inspection predominately relies on visual inspection to detect anyMagnetic particle inspection predominately relies on visual inspection to detect anyindications that form. Therefore, lighting is a very important element of the inspectionindications that form. Therefore, lighting is a very important element of the inspectionprocess. Obviously, the lighting requirements are different for an inspection conductedprocess. Obviously, the lighting requirements are different for an inspection conductedusing visible particles than they are for an inspection conducted using fluorescentusing visible particles than they are for an inspection conducted using fluorescentparticles. The lighting requirements for each of these techniques, as well as how lightparticles. The lighting requirements for each of these techniques, as well as how lightmeasurements are made, are discussed below.measurements are made, are discussed below.

Light Requirements When Using Visible ParticlesLight Requirements When Using Visible Particles

Magnetic particle inspections that use visible particles can be conducted using naturalMagnetic particle inspections that use visible particles can be conducted using naturalor artificial lighting. When using natural lighting, it is important to keep in mind thator artificial lighting. When using natural lighting, it is important to keep in mind thatdaylight varies from hour to hour. Inspector must constantly stay aware of the lightingdaylight varies from hour to hour. Inspector must constantly stay aware of the lightingconditions and make adjustments when needed. To improve the uniformity of lightingconditions and make adjustments when needed. To improve the uniformity of lightingfrom one inspection to the next, the use of artificial lighting is recommended. Artificialfrom one inspection to the next, the use of artificial lighting is recommended. Artificiallighting should be white whenever possible and white flood or halogen lamps are mostlighting should be white whenever possible and white flood or halogen lamps are mostcommonly used. The light intensity is required to be 100 footcommonly used. The light intensity is required to be 100 foot--candles at the surfacecandles at the surfacebeing inspected. It is advisable to choose a white light wattage that will providebeing inspected. It is advisable to choose a white light wattage that will providesufficient light, but avoid excessive reflected light that could distract from thesufficient light, but avoid excessive reflected light that could distract from the

inspection.inspection.


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UV or Black lightUV or Black light Light Requirements When Using Fluorescent ParticlesLight Requirements When Using Fluorescent Particles Ultraviolet LightingUltraviolet Lighting

When performing a magnetic particle inspection using fluorescent particles,When performing a magnetic particle inspection using fluorescent particles,the condition of the ultraviolet light and the ambient white light must bethe condition of the ultraviolet light and the ambient white light must bemonitored. Standards and procedures require verification of lens conditionmonitored. Standards and procedures require verification of lens conditionand light intensity. Black lights should never be used with a cracked filter asand light intensity. Black lights should never be used with a cracked filter asthe output of white light and harmful black light will be increased. Thethe output of white light and harmful black light will be increased. Thecleanliness of the filter should also be checked regularly since a coating ofcleanliness of the filter should also be checked regularly since a coating ofsolvent carrier, oil, or other foreign material can reduce the intensity or lightsolvent carrier, oil, or other foreign material can reduce the intensity or light

by as much as 50%. The filter should be checked visually and cleaned asby as much as 50%. The filter should be checked visually and cleaned asnecessary before warmingnecessary before warming--up the light.up the light. For UV lights used in component evaluations, the normally accepted intensityFor UV lights used in component evaluations, the normally accepted intensity

is 1000mwatts/ cm2 when measured at 15 inches from the filter faceis 1000mwatts/ cm2 when measured at 15 inches from the filter face(requirements can vary from 1000 to 1200mwatts/ cm2). The required check(requirements can vary from 1000 to 1200mwatts/ cm2). The required checkshould be performed when a new bulb is installed, at startup of the inspectionshould be performed when a new bulb is installed, at startup of the inspectioncycle, if a change in intensity is noticed, or every eight hours if in continuouscycle, if a change in intensity is noticed, or every eight hours if in continuoususe. Regularly checking the intensity of UV lights is very important becauseuse. Regularly checking the intensity of UV lights is very important becausebulbs lose intensity over time. In fact, a bulb that is near the end of itsbulbs lose intensity over time. In fact, a bulb that is near the end of itsoperating life will often have an intensity of only 25% of its original output.operating life will often have an intensity of only 25% of its original output.Black light intensityBlack light intensity


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will also be affected by voltage variations, so it is important to providewill also be affected by voltage variations, so it is important to provideconstant voltage to the light. A bulb that produces acceptable intensity atconstant voltage to the light. A bulb that produces acceptable intensity at120/230 volts will produce significantly less at 110/200 volts.120/230 volts will produce significantly less at 110/200 volts.

Ambient White LightingAmbient White LightingWhen performing a fluorescent magnetic particle inspection, it is important toWhen performing a fluorescent magnetic particle inspection, it is important tokeep white light to a minimum as it will significantly reduce the inspectorskeep white light to a minimum as it will significantly reduce the inspectorsability to detect fluorescent indications. Light levels of less than 2fc areability to detect fluorescent indications. Light levels of less than 2fc are

required by most procedures and some procedures require it to be less thanrequired by most procedures and some procedures require it to be less than0.5fc at the inspection surface. Some specifications require that a white light0.5fc at the inspection surface. Some specifications require that a white lightintensity measurement be made at 15 inches from a UV light source to verifyintensity measurement be made at 15 inches from a UV light source to verifythat the white light is being removed by the filter.that the white light is being removed by the filter.

White Light for Indication ConfirmationWhite Light for Indication ConfirmationWhile white light is held to a minimum in fluorescent inspections, proceduresWhile white light is held to a minimum in fluorescent inspections, proceduresmay require that indications be evaluated under white light. The white lightmay require that indications be evaluated under white light. The white light

requirements for this evaluation are the same as when performing anrequirements for this evaluation are the same as when performing aninspection with visible particles. The minimum light intensity at the surfaceinspection with visible particles. The minimum light intensity at the surfacebeing inspected must be 100fc.being inspected must be 100fc.


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Light MeasurementLight Measurement

Light intensity measurements are made using a radiometer. A radiometer is anLight intensity measurements are made using a radiometer. A radiometer is aninstrument that translates light energy into an electrical current. Light striking a siliconinstrument that translates light energy into an electrical current. Light striking a siliconphotodiode detector causes a charge to build up between internal layers. When anphotodiode detector causes a charge to build up between internal layers. When anexternal circuit isexternal circuit isconnected to the cell, an electrical current is produced. This current is linear withconnected to the cell, an electrical current is produced. This current is linear withrespect to incident light. Some radiometers have the ability to measure both white andrespect to incident light. Some radiometers have the ability to measure both white andUV light, while others require a separate sensor for each measurement. The sensingUV light, while others require a separate sensor for each measurement. The sensingarea should always be kept clean and free of materials that could reduce or obstructarea should always be kept clean and free of materials that could reduce or obstructlight reaching the sensor.light reaching the sensor.

Radiometers are relatively unstable instruments and readings often changeRadiometers are relatively unstable instruments and readings often changeconsiderably over time. Therefore, they must be calibrated regularly. They should beconsiderably over time. Therefore, they must be calibrated regularly. They should becalibrated at least every six months. A unit should be checked to make sure itscalibrated at least every six months. A unit should be checked to make sure itscalibration is current before taking any light readings.calibration is current before taking any light readings.

Ultraviolet light measurements should be taken using a fixture to maintain a minimumUltraviolet light measurements should be taken using a fixture to maintain a minimumdistance of 15 inches from the filter face to the sensor. The sensor should be centereddistance of 15 inches from the filter face to the sensor. The sensor should be centered

in the light field to obtain the peak reading. UV spot lights are often focused whichin the light field to obtain the peak reading. UV spot lights are often focused whichcauses intensity readings to vary considerable over a small area. White lights arecauses intensity readings to vary considerable over a small area. White lights areseldom focused and, depending on the wattage, will often produce in excess of theseldom focused and, depending on the wattage, will often produce in excess of the100fc at 15 inches.100fc at 15 inches.


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Daily Test to be done.Daily Test to be done.

Check the Maximum output of the Machine.Check the Maximum output of the Machine.

Check the intensity of the Black /UV light .Check the intensity of the Black /UV light .

Proper agitation of the bath.Proper agitation of the bath.

Check with ASTM Pie field for the optimum current used(field adequacy & directionCheck with ASTM Pie field for the optimum current used(field adequacy & directionof magnetization).of magnetization).

Check with digital gauss meter with Hall probe meter for proper field strength forCheck with digital gauss meter with Hall probe meter for proper field strength forsome special cases.some special cases.

Check with QQI shim or Castrol strips in Multi directional machine for optimum fieldCheck with QQI shim or Castrol strips in Multi directional machine for optimum fieldstrength at all places.strength at all places.

Check with Ketos ring for sufficient subCheck with Ketos ring for sufficient sub--surface sensitivity of the Machine, forsurface sensitivity of the Machine, formachines having HWDC/ FWDC / 3 Phase Full wave DC machine.machines having HWDC/ FWDC / 3 Phase Full wave DC machine.

Check the concentration strength of the Bath.Check the concentration strength of the Bath.

Check for the contamination of the Bath.Check for the contamination of the Bath.

Check proper demagnetization with the help of Residual field meter or Digital meter.Check proper demagnetization with the help of Residual field meter or Digital meter. Check for any loose collection .Check for any loose collection .


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safetysafety

Ensure the UV filter glass is not cracked or broken.Ensure the UV filter glass is not cracked or broken.

Use UV spectacles for protecting your eye and better indications.Use UV spectacles for protecting your eye and better indications.

The person inspecting should not wear dark glasses or photo chromic glasses.The person inspecting should not wear dark glasses or photo chromic glasses.

Ensure the person is inside the dark room before inspection with Fluorescent particle.Ensure the person is inside the dark room before inspection with Fluorescent particle.

Use hand protective cream when using oil base powder.Use hand protective cream when using oil base powder.

Use hand gloves if necessary.Use hand gloves if necessary.

Please try to get the MSDS from the suppliers for all the chemicals & oils used.Please try to get the MSDS from the suppliers for all the chemicals & oils used.

Precaution against inhalation , eye contact , skin irritation should be taken.Precaution against inhalation , eye contact , skin irritation should be taken. When using oil base please know the flash point of the liquid used.When using oil base please know the flash point of the liquid used.

Never keep the Residual field indicator close to any magnetic field.Never keep the Residual field indicator close to any magnetic field.

The open output voltage in the MPI machine should not exceed more than 24The open output voltage in the MPI machine should not exceed more than 24 --2828Volt.Volt.

Ensure there is no electrical leakage, proper grounding should be done.Ensure there is no electrical leakage, proper grounding should be done.

Ensure unnecessary use of high current .Ensure unnecessary use of high current . Avoid improper contact of parts , heavy arcing might take place.Avoid improper contact of parts , heavy arcing might take place.


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QuestionsQuestions1.1. Which is the best magnetic particle to be usedWhich is the best magnetic particle to be used

at a temperature above 100 C?at a temperature above 100 C?

2.2. What is the difference between Residual FieldWhat is the difference between Residual FieldMeter & Digital Gauss meter?Meter & Digital Gauss meter?

3.3. The best current for SubThe best current for Sub-- surface defect ?surface defect ?Why?Why?

4.4. The best Demagnetization Technique? OrThe best Demagnetization Technique? OrProcess.Process.

5.5. Batch of nuts & bolts, the best & the fastestBatch of nuts & bolts, the best & the fastestmethod of demagnetization?method of demagnetization?


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QuestionsQuestions

1.1. Quick break circuit when is it used?Quick break circuit when is it used?2.2. White light emission from the black light or aWhite light emission from the black light or a

UV source should not exceed?UV source should not exceed?

3.3. The best magnetization current for weldThe best magnetization current for weld

inspection & the particle?inspection & the particle?

4.4. Best method of inspection Continuous orBest method of inspection Continuous orResidual ?Residual ?

5.5. Which particle Dry or Wet has got betterWhich particle Dry or Wet has got betterpermeability ? Mobility ?permeability ? Mobility ?


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QuestionsQuestions

1.1. Toroidal Technique why is it used ?Toroidal Technique why is it used ?

2.2. Output voltage should be withinOutput voltage should be within------------ in a MPIin a MPImachine.machine.

3.3. In Multi direction machine the First MagneticIn Multi direction machine the First MagneticField to be given in the component is?Field to be given in the component is?

4.4. The second field ? & why?The second field ? & why?

5.5. When is Demagnetization not required afterWhen is Demagnetization not required aftermagnetizing the component.magnetizing the component.

6.6. The best direction of the Demagnetizer coilThe best direction of the Demagnetizer coilopening.opening.


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