radio graphic artefacts

Upload: puiuvoicu

Post on 06-Apr-2018

225 views

Category:

Documents


0 download

TRANSCRIPT

  • 8/3/2019 Radio Graphic Artefacts

    1/10

    MSR/ART-TWI Issue 1 Date 29/08/04 Page 1 of 10

    THE WELDING INSTITUTE

    Radiographic Artifacts

  • 8/3/2019 Radio Graphic Artefacts

    2/10

    MSR/ART-TWI Issue 1 Date 29/08/04 Page 2 of 10

    THE WELDING INSTITUTE

    Light Fog

    Light leaks

    Caused by: Faulty film cassette, light leaks

  • 8/3/2019 Radio Graphic Artefacts

    3/10

    MSR/ART-TWI Issue 1 Date 29/08/04 Page 3 of 10

    THE WELDING INSTITUTE

    Crimping / Pressure Marks

    Black appearance crimping after exposure

    White appearance crimping before exposure

  • 8/3/2019 Radio Graphic Artefacts

    4/10

    MSR/ART-TWI Issue 1 Date 29/08/04 Page 4 of 10

    THE WELDING INSTITUTE

    Film Scratches

    Caused by: Mishandling of the film, mechanical damage.

  • 8/3/2019 Radio Graphic Artefacts

    5/10

    MSR/ART-TWI Issue 1 Date 29/08/04 Page 5 of 10

    THE WELDING INSTITUTE

    Static Discharge

    Lightening like appearance, but may also be mottled in

    appearance.

    Caused by: Pulling the film quickly from between the

    intensifying screens in a dry atmosphere, causing static

    electricity creating density on the radiograph.

  • 8/3/2019 Radio Graphic Artefacts

    6/10

    MSR/ART-TWI Issue 1 Date 29/08/04 Page 6 of 10

    THE WELDING INSTITUTE

    Chemical Marks

    Caused by: Mishandling of processing chemicals

  • 8/3/2019 Radio Graphic Artefacts

    7/10

    MSR/ART-TWI Issue 1 Date 29/08/04 Page 7 of 10

    THE WELDING INSTITUTE

    Water Marks

    Areas of low density on the radiograph

  • 8/3/2019 Radio Graphic Artefacts

    8/10

    MSR/ART-TWI Issue 1 Date 29/08/04 Page 8 of 10

    THE WELDING INSTITUTE

    Dust, Lint and Grime Marks

  • 8/3/2019 Radio Graphic Artefacts

    9/10

    MSR/ART-TWI Issue 1 Date 29/08/04 Page 9 of 10

    THE WELDING INSTITUTE

    Reticulation

    Appearance can either be a net like structure or leather

    grain.

    Caused by excessive temperature variations in the processing

    tanks, causing the emulsion to rupture. Very rare artifact today

    due to the flexibility of modern base materials and emulsions.

  • 8/3/2019 Radio Graphic Artefacts

    10/10

    MSR/ART-TWI Issue 1 Date 29/08/04 Page 10 of 10

    THE WELDING INSTITUTE

    Diffraction Mottle

    The appearance is fine porosity or Herringbone porosity

    throughout the weld area on the radiograph

    Occurs in a radiograph due to the grain size or orientation of

    certain materials such as stainless steels and aluminum.

    It may be reduced or eliminated by reducing the wavelength

    or by changing the radiation angle by approximately 5o