1

Appendix 2 Senior Welding Inspector

Technical Notes Rad. U/T. MPI & Penetrant

Radiography: X ray: KV as low as possible = Best definition. Generally 60kV lowest is OK for lower density aluminium. Normally a minimum of 140 kV is required for steels but must be increased as thickness increases Focal Spot: The larger the focal spot the longer must be the FFD Gamma: SFD typically 500mm but varies greatly, Double the distance

= 4 x original exposure

Typical source size of 1.5mm x 1.5mm Ytterbium: Used on thickness under 12 mm (Costly) Iridium 192: Used for applications thickness 12 to 60mm Cobalt 60: Used on thickness over 40 to 200 mm Lead screens: 0.1mm front and 0.15 mm back but often 0.125 front/back

Used on all gamma and x-ray above 120 kV Development: Typically 4 min’s at 20 ºC Density: Typically 2-3.5 Sensitivity: Typically 2% or less. (IQI Diameter of smallest wire/thickness x 100) Viewing Light Conditions: 20 lux. Viewer able to view up to density of 4

Minimum screen luminance 100,000 cd/m2

2

Appendix 2 Senior Welding Inspector Ultrasonic: Probes: Check for lamination 0º Compression Probe Plate thickness <10 mm 70º Plate thickness 10 – 15 mm 60º-70º Plate thickness 15 + mm 45º- 60º Plate thickness >50 mm 45º only Mhz: Normal welds 4-5 MHz Larger grains lower value. Higher value = less pen Record crystal size (Usually 10mm) single or twin? Sensitivity: Which calibration block V1/V2? Hole diameter + depth (side drilled hole) Couplant: Record of the type used

3

Appendix 2 Senior Welding Inspector Magnetic Particle: Through paint up to 50 microns With DC Sub surface defects can be detected approximately 2mm deep (depends on strength of current) Above 50 ºC up to 3150C usually dry powder Yokes: No current recorded lift off of > 4.5kg Normally AC but can be DC Prods: 6 amp/mm of space i.e. 200mm = 1200 amps Space and amperage must be recorded. 7.5 – 20 cm (75 – 200 mm) All must record 2 directions at 90º Burmah Castrol Strip type 1 indications of 3 lines

4

Appendix 2 Senior Welding Inspector Penetrant: Temperature: 10ºC to 50 ºC Dwell/Contact time 5 – 60 min’s Evaluation time 10 – 30 min’s Viewing Light Conditions for Penetrant and MPI: Normal light: 500 lux minimum Fluorescent: Use UVA lamp minimum power 1000 microwatt/cm2 Light levels: Below 20 lux ambient light