Appendix A- Magnetic Particle Booth Calibration Requirements.pdf

DOWTY PROPELLERS STANDARD PRACTICES MANUAL

60-00-00

NDT 2DAP

Mar 31/23

GE AVIATION SYSTEMS LTD PROPRIETARY INFORMATION

Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

F. All parts that are subject to direct contact circular magnetisation shall be visually inspected for “arc burns”. Any parts found to have arc burns shall be reported to the Supervision and/or the Level 3.

9. Magnetic Detection Media

A. Magnetic ink particles shall conform to AMS 3044, AMS 3045 or AMS 3046.

B. For the inspection of raw materials, forgings and castings, the use of a water based vehicle with suitable conditioner may be used.

C. For the in-process, final and in-service inspection of finished or semi-finished parts, oil based inks shall be used. The oil used for the liquid vehicle shall conform to AMS 2641.

D. Particle concentration shall be within the range of 0.1 to 0.3 ml per 100ml sample.

10. Demagnetisation

A. When using AC demagnetisation, the part(s) shall be subjected to a field with a peak value greater than, and in nearly the same direction as the field used during examination. The AC field is then decreased gradually to zero. When using an AC demagnetising coil, hold the part approximately 12 inches (30cm) in front of the coil and move it slowly through the coil and at least 36 inches (100cm) beyond the coil while the current is flowing. Parts with complex configuration may be rotated through the coil. The process may be repeated as necessary.

B. When using DC demagnetisation, the field shall be higher than, and it nearly the same direction as the field used during examination. The field shall then be reversed, decreased in magnitude and if required, repeated until the residual field is at an adequate level.

C. After demagnetisation, the residual field value shall not exceed 3 Gauss anywhere on the part.

11. Quality Control

A. Magnetic particle inspection equipment shall be checked for performance and accuracy when installed, at intervals stated in Table 11.1, after malfunction or when maintenance may affect accuracy.

Inspection measuring and test equipment shall be calibrated and certified having a known valid relationship to National Institute of Standards and Technology (NIST) in accordance with ANSI Z 540-1, or system conforming to ISO 10012-1.

NOTE: All control checks, performance tests and calibrations shall be recorded on an appropriate control sheet and retained in accordance with QMP25.

B. Any equipment which fails any of these tests is unacceptable. Any unacceptable equipment shall be corrected or replaced before performing further processing of parts. It shall be determined if parts inspected prior to the failure should be re-inspected.

C. Machine Ammeter Accuracy.

(1) Ammeters shall be tested for accuracy at intervals stated in Table 11.1 in accordance with II148.

(2) A calibrated ammeter and shunt, which is traceable to a national standard, shall be connected in series with the output circuit.

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GE AVIATION SYSTEMS LTD PROPRIETARY INFORMATION

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(3) Take comparative readings at a minimum of 5 output levels covering the entire operating range of the ammeter.

(4) A machine ammeter reading that deviates more than +/- 10% from the current shown by the calibrated ammeter of 50 amperes (whichever is greater) is not acceptable.

D. Machine Shot Timer

(1) The machine shot timer shall be checked at intervals stated in Table 11.1 in accordance with II148.

The pulse timer shall be accurate to within +/- 0.1 second.

E. Internal Short Check.

(1) A machine internal short test shall be performed at intervals stated in Table 11.1 in accordance with II148. An ammeter reading above 20 amperes, when the current is activated, indicates an internal short. The equipment shall be repaired prior to processing parts.

F. Quick/Fast Break Check

(1) For machines fitted with quick/fast break equipment, verify operation at intervals stated in Table

11.1. This shall be carried out in accordance with the manufacturer’s instructions.

G. Gauss Meters (Hall Effect Meters)

(1) Calibrate gauss meters at intervals stated in Table 11.1. This shall be carried out to the manufacturer’s requirements at a minimum of 3 positions through the working range.

H. Field Indicators

(1) Calibrate field Indicators, used to check residual magnetic fields, at intervals stated in Table 11.1.

This shall be carried out to the manufacturer’s requirements through the working range.

I. UV-A Radiometers and Visible Light Photometers

(1) UV-A Radiometers and Visible light Photometers shall be calibrated at intervals stated in Table 11.1.

(2) Meters shall be digital readout. For UV-A read in µW/cm². For Visible light read in foot-candles (fc) or Lux.

(3) Meters shall be checked at 3 positions minimum across the working range, to an accuracy of +/- 5% of the master meter.

(4) UV-A Radiometers shall have a spectral response in the range of 320 to 400 nm.

J. Lighting

(1) Lighting levels shall be verified at intervals stated in Table 11.1.

(2) Portable, hand-held, permanently mounted or fixed UV-A lamps used to inspect parts shall have a minimum intensity of 1000 µW/cm² when checked at a distance of 15 inches (38cm) from the front face of the filter to the sensor.

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GE AVIATION SYSTEMS LTD PROPRIETARY INFORMATION

Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

(3) Where lamps are physically too large to directly illuminate the examination surface, special lighting sources such as UV-A pencil lights shall have a minimum intensity of 1000µw/cm² when checked at the inspection surface.

(4) Ambient Visible light levels in the inspection areas shall not exceed 21.5 Lux (2 fc) when checked at the part surface.

(5) Visible light used for the interpretation of indications found with fluorescent magnetic particle inspection, shall have a minimum intensity of 1076 Lux (100 fc) at the inspection surface.

(6) Battery powered UV-A Lamps used to inspect parts shall have their intensity measured prior to and after each use.

(7) UV-A lamps shall be checked at the interval specified in Table 11.1 for cleanliness and integrity and shall be cleaned, repaired, or replaced as appropriate. Replace cracked or broken ultraviolet filters immediately. LED UV-A lamps used to inspect parts shall be checked daily to ensure all diode elements are operational. If any diode element is not operational, the condition shall be corrected, or the unit replaced. The operational check may be performed by placing a white sheet of paper over the lamp filter to view the transmitted light from each diode.

K. Magnetic Inks.

(1) Magnetic inks shall meet the requirements of section 9. In addition, they shall meet the following requirements and be verified at intervals stated in Table 11.1.

(2) When new suspensions are mixed, a sample of the new mix shall be taken and stored of in darkened conditions for reference.

(3) Concentration and contamination checks shall be carried out at the start of each shift, after any period where the agitation of suspension has been stopped for 10 minutes or longer, or when the bath is changed or adjusted.

(4) Allow the bath to circulate for a minimum of 30 minutes prior to taking a sample.

(5) Place a 100ml sample of in-use suspension in a centrifuge tube.

(6) Demagnetise the sample and allow to stand for a minimum of 30 minutes for water based inks and 60 minutes for oil based inks.

(7) Read the volume of particles which have settled. This shall be within the range of 0.1 to 0.3 ml per 100 ml sample.

(8) Examine the settled particles, under both UVA and Visible light, for layers, bands or striations different in colour or appearance. These layers, bands or striations indicate contamination. If the contamination exceeds 30% of the settled particles, the bath shall be changed. Clouding or fluorescence of the vehicle to the extent that the markings on the centrifuge tube, which are between 5 ml and 25 ml, cannot be seen when viewed through the vehicle indicate the bath must be replaced before further use.

(9) Any noticeable reduction in fluorescent brightness or colour, when compared to the as-new reference sample, is unacceptable.

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GE AVIATION SYSTEMS LTD PROPRIETARY INFORMATION

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(10) When any unacceptable condition is identified, the suspension must be changed / adjusted prior to further processing of parts.

(11) When using a water vehicle for the inspection of raw materials, castings or forgings, a water break test shall be performed and verified at intervals stated in Table 11.1.

(12) The water break test is acceptable if an even, continuous film forms over the entire area under test.

If there is a break in the film, the part has not been cleaned correctly or there is insufficient wetting agent in the bath and the test is unacceptable. The part(s) shall be re-cleaned or wetting agent added to the bath to make the test acceptable.

L. System Performance Test

(1) For current flow, a ring specimen complying with AS 5282 is the preferred method for system verification in accordance with ASTM E 1444.

(2) TP 1, 2 or 3 may also be used for current flow system verification. Other test pieces may be used when agreed by the Dowty Propellers Level 3.

(3) For Magnetic flow/coil, a standard test piece shall be developed (TP 4 or similar) for the verification of the process. The current value and position (within the coil) shall be established. These parameters shall then be used daily for this performance test.

Mar 31/23

GE AVIATION SYSTEMS LTD PROPRIETARY INFORMATION

Use or disclosure of data contained on this sheet is subject to the restrictions on the cover or first page.

TABLE 11.1

Testing and Verification Intervals

TEST

INTERVAL

REFERENCE

MACHINE AMMETER 6 MONTHLY 11.C

SHOT TIMER 6 MONTHLY 11.D

INTERNAL SHORTING 6 MONTHLY 11.E

QUICK/FAST BREAK 6 MONTHLY 11.F

GAUSS METER (HALL-

EFFECT)

6 MONTHLY 11.G

FIELD INDICATORS 6 MONTHLY 11.H

UV-A RADIOMETER &

PHOTOMETER

6 MONTHLY 11.I

UV-A LAMP INTENSITY DAILY 11.J

UV-A LAMP INTENSITY

(BATTERY)

PRIOR TO AND AFTER USE 11.J

UV-A LAMP INTEGRITY DAILY 11.J

VISIBLE LIGHT INTENSITY WEEKLY 11.J

AMBIENT VISIBLE LIGHT WEEKLY 11.J

INK CONCENTRATION EACH SHIFT 11.K

INK CONTAMINATION EACH SHIFT 11.K

WATER BREAK TEST PRIOR TO USE 11.K

SYSTEM PERFORMANCE

TEST

DAILY 11.L