8/12/2019 MPI - 008M004 Magnetic Flux Indicator - MagnaFacts

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Magnaflux7 Magnetic Flux Indicator

Magnaflux7 Type G (General Use) Magnetic Flux Indicators

are flexible indicators used to detect appropriate levels of

magnetic field strength and directional orientation during the

magnetic particle testing process.

Magnaflux7 Magnetic Flux Indicators are manufactured

from permeable magnetic steel sandwiched

between two protective 0.002 brass plates.

The central magnetic steel plate contains three

milled slots with widths of .0075, .009 and .010 and

common depths. The slots serve as sample test

flaws with wider slots generating greater

amounts of magnetic flux leakage and larger magnetic

particle indications than narrower ones.

By using Magnaflux7 Magnetic Flux Indicators, magnetic

field levels can be properly set and continously checked

during the MPI process for their sufficiency in detecting

defects of the sizes indicated on the test strip.

ADVANTAGES & LIMITATIONS: Easy to use. Better suited

for non-aerospace applications. More durable than QQI and

capable of repeated use. Can be used in wet or dry MPI

applications, but are not suited for use with multidirectional

field testing. Rigidity can prevent application in test situations

that require intimate test strip contact with parts. Conforms

to ASTM E 709-08 and E 1444-11, Annex A3.

Magnaflux7 QQI

Magnaflux7 Quantitative Quality Indicators (QQI), are similar

to Magnaflux7 Magnetic Flux Indicators in that they are used

to assure that proper field strength and direction are

maintained throughout the magnetic particle testing process.

Unlike magnetic flux indicators, Magnaflux7 QQI are

manufactured from thin, flexible strips (shims) of

.002 and .004 steel photoetched with concentric

circle and cross bar defect patterns to depths of

20%, 30% or 40% of the shims thickness. The size

and thickness of the shims allow them to more

intimately conform to the surface shape of test parts

to produce a more accurate read of MPI field strength and

direction. While their design and construction can offer a

more exacting indication of field strength, greater time andcare must be taken when adhering and removing a QQI

from a test part to prevent it being damaged.

ADVANTAGES & LIMITATIONS: Better suited for

Aerospace applications and those requiring a more exacting

read of magnetic field strength and direction. Can be used

with multidirectional fields. Thin, flexible construction affords

intimate contact with test part but must be more carefully

applied/removed. Can be reused with care but does not offer

the durability or level of repeated use of the Magnaflux7Magnetic

Flux Indicator. Conforms to ASTM E 1444-11, Annex A2.

Vs.

While differences exist among NDT professionals pertaining to their preference for using magnetic flux indicators or

QQI to measure field strength and direction during magnetic particle testing, the truth is that both have a role to play. A

comparison of the benefits of each has been provided below to help customers determine which may be best suitedfor their particular NDT application, and when one may offer distinct advantages over the other.

MAGNAFACTSMAGNAFLUX . 3624 WEST LAKE AVENUE . GLENVIEW, ILLINOIS 60026 . (847) 657-5300 . WWW.MAGNAFLUX.COM

Magnaflux7 Magnetic Flux Indicator Magnaflux7 QQI (Quantitative Quality Indicators)

Part Number: 008M004 Part Numbers:

519632 519630 521049 519631 521048

INFORMATION TO IMPROVE YOUR NDT PROCESS.