1. what is optimal temperature for hand developing a radiograph
    68*F or 20*C
  2. developing:
    converts latent image to visible image (converts exposed silver halide to elemental silver )
  3. what happens to exposed silver halide during developing
    turns to black metallic silver
  4. accelerators:
    increase the activity of the developer by causing the emulsion layer to swell and soften
  5. Preservatives:
    prevent rapid oxidation thats associated with alkaline developers
  6. restrainers:
    limits the developing agent to the exposed crystals
  7. Hardners:
    used in automatic processors to prevent excessive emulsion swelling
  8. Solvent:
    dissolve the chemicals
  9. why to we rinse radiographs
    • to prevent carryover contamination to fixer; developer - alkaline 
    • fixer - acid
  10. how long is a radiograph rinsed for
    30 sec in circulating water
  11. what happens to a film that is not fixed properly
    film will discolor and darken with exposure to light
  12. what dose fixing a radiograph do
    removes unexposed silver halide from film, hardens the gelatin coating
  13. why is rinse not used in automatic processor?
    the rollers remove excess developer before it reaches the fixer
  14. fixing:
    dissolves and removes unexposed silver halide crystals from the film emulsion layer; changes the apperance of radiograph to clear (trasparent) look except the black metalic silver portions remain the same
  15. Preservatives:
    prevent decomposition of fixing agent
  16. Hardeners:
    prevent swelling of emulsion layer and thus shortens drying time  (prevents film from becoming water logged
  17. Acidifiers:
    • neutralize any alkaline developer from developing solution 
    •  accelerates the action of other chemicals in the fix solution
  18. Buffers:
    chemical compounds used to maintain the desired PH
  19. solvent:
    water-carries the silver halide away from the film
  20. what temp is fixing done?
    68* F
  21. how long do we leave in fixer ?
    10 min - rule of thumb is double the developing time ! (5 min )
  22. how long is it left in developer ?
    10 min
  23. final wash -
    to remove all the processing chemicals from film; water temp - 60 -70* F ;time- 30 min with periodic agitation
  24. what are advantages to automatic processor?
    produces a dry radiograph quickly; and reduces variables
Card Set
hand developing