1 / 37

FILM PROCESSING

FILM PROCESSING. DR SAMY I AL-AGHA A.PROFESSOR OF RADIOLOGY ALAZHAR GAZA UNIVERCITY. FILM PROCESSING. DEFINITION MECHANISM OF FORMATION OF LATENT IMAGE: Ag Br + X-ray photon---- Ag + Br- Ag+ ions form minute amount amount of ppt called Specks or spot of metallic Ag atoms

marli
Download Presentation

FILM PROCESSING

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. FILM PROCESSING DR SAMY I AL-AGHA A.PROFESSOR OF RADIOLOGY ALAZHAR GAZA UNIVERCITY

  2. FILM PROCESSING • DEFINITION • MECHANISM OF FORMATION OF LATENT IMAGE: Ag Br + X-ray photon----Ag + Br- Ag+ ions form minute amount amount of ppt called Specks or spot of metallic Ag atoms Bromide ions -bromine gas

  3. LATENT IMAGE Latent image is formed of Ionized Ag halide+small amount of Ag+ spots • In Latent image there will be 1-Totally exposed crystals 2-Partially exposed crystals 3-Unexposed crystals

  4. FILM PROCESSING The major processing solutions are: 1-Developer 2-Fixer

  5. DEVELOPER • Phenidone (P) &Hydroquinone (Q) • 2AgBr + Hydroquinone-----2Ag+quinone+2HBr

  6. DEVELOPER • BUFFERING SYSTEM • Boric acid • NaOH

  7. DEVELOPER • Preservative • Na sulphite • To prevent oxidation

  8. DEVELOPER • Restrainer (Anti fog agent) • 1-Benzotriazole • 2-KBr

  9. DEVELOPER • Sequestrating agent • DTA Na salt • To prevent precipitation of Ca on film and developer tanks

  10. DEVELOPER • Hardening agent • Aldehyde &sulphate • To decrease swelling and softenning of emulsion

  11. DEVELOPER • Wetting agent • Detergent based derivatives • To produce uniform development of films

  12. DEVELOPER • Anti-Frothant

  13. DEVELOPER • Fungicidal • Recirculating water at high pressure 1.5 L/ min

  14. DEVELOPER • Starter solution • KBr +Acetic acid

  15. DEVELOPER DEVELOPER

  16. FIXER • Ammonium or Na Thiosulphate • p H 4.2-4.9 • Form permenant image

  17. FIXER • 1-Fixing agent • 2-Acid • 3-Buffer • 4-Preservative • 5-Hardener • 6-Solvent

  18. FIXER • FIXING AGENT • Na or Ammonium thiosulphate • * Clearing time 8-10sec in ammonium • 4-5 mins in Na • *Fixing time = 1.3xclearing time (Ammoni) • =2xclearing time(Na )

  19. FIXER • ACID &HARDENERS • 1-Acetic acid &Al Cl as hardener • 2-Sulphoric acid &Al sulphate as hardener

  20. FIXER • BUFFERS • Acetic Acid +Na or K sulphite

  21. FIXER • Hardeners ( In rapid film processing) • Al Cl3 • Al2(SO4)3

  22. FIXER FIXERS

  23. FILM PROCESSING • Totally exposed crystals--developer------black metallic Ag---Fixer-black • Partially exposed----developer&fixer--Gray • Unexposed crystals----developer&fixer--white.

  24. DARK ROOM • Site • Size • Lightening • Ventilation • Temp&humidity • Workable bench • Cleaninig

  25. LIGHTS IN DARK ROOM 1-Ordinary light 2-Safe light Specifications of the safe light • Wave length(orange or yellow) • Wattage of bulb(15watts) • Distance from light&workable bench(4feets) • Exposure time (4mints) • No of safe lights in average room(2)

  26. SAFE LIGHT COIN TEST

  27. EQUIPMENTS OF DARK ROOM 1-PROCESSING TANKS 2-DRYER 3-FILM RACKS(HANGERS) 4-STORAGE SPACE

  28. STEPS OF FILM PROCESSING 1-DEVELOPER(5mints) 2-RINSING WITH RUNNING WATER(10sec) 3-FIXATION (10 mints) 4-WASHING (20mints) 5-DRYING

  29. METHODS OF PROCESSING A-MANUAL(CONVENTIONAL) 1-Visual(inspection)method 2-Fixed time temp method B-SPEED PROCESSING 1-Automatic processing 2-Polaroid rate processing 3-Self contained processing solution 4-Ingectable films 5-Rapid processing chemicals

  30. MANUAL PROCESSING 1-VISUAL(INSPECTION) METHOD Advantage Disadvantage 2-FIXED TIME TEMP METHOD • Scientific standardized &reliable • The higher the temp-less the time of developing and vise versa

  31. RAPID PROCESSING METHODS 1-AUTOMATIC PROCESSING • It takes 1-5mints • Used for intra or extra oral films • No rinsing • Higher temp of processing solutions • Higher concentration of processing solutions • Regular replenshing of processing solutions

  32. AUTOMATIC PROCESSING ADVANTAGES • Time saving • Standardized results • No use of dark room during processing DISADVANTAGES • High cost • Regular mintanence&services • Processing specific NO of films at one time • High temp--more chemical fumes

  33. RAPID PROCESSING METHODS 2-POLAROID PROCESSING METHOD • Emulsion is coated on paper backing • Speed processing without need of dark room • Good for emergency • Needs high exposure time

  34. RAPID PROCESSING METHODS 3-SELF CONTAINED PROCESSING • 2Packets attached to the film packet • After film exposure we pull the 2 packetsone after the other to pour the developer and massage for 30sec then the fixer then the film is unrapped • Speedy&easy technique • Final image may be fogged due to non rinsing

  35. RAPID PROCESSING METHODS 4-INJECTABLE INTRA ORAL FILMS • Film packet have injectable site(tunnel) • No lead foil backing or black paper • After exposure-injection of developer for 30sec-fixer

  36. RAPID PROCESSING METHODS 5-RAPID PROCESSING CHEMICALS • High concentration of ready made solutions • Developing time is 10-30 sec • Less contrast • Film fogging • Rapid deterioration of solutions

  37. END

More Related