FSI Flashcards
What is the basis of the pH scale?
Pure water (H2O) is chosen as the basis of the pH scale.
What ions does water slightly ionize into?
Water slightly ionizes into H+ ions and OH- ions.
What is the pH range for most developers in automatic processing?
The pH range for most developers is 9.6-10.6.
What pH range should fixers for automatic processing maintain?
Fixers should maintain a pH range of 4.2-4.9.
What is the function of a developer?
A developer must convert exposed crystals to black metallic silvers.
What must a developer differentiate between?
A developer must differentiate between exposed and unexposed silver halide crystals.
What is the function of an accelerator in developer constituents?
An accelerator controls developer activity by ensuring the correct pH value.
What are common agents used as accelerators?
Common agents include Sodium Hydroxide and Potassium Hydroxide.
What is the function of a buffer in developer constituents?
A buffer helps maintain pH and therefore activity by absorbing harmful by-products of development.
What agents are used as buffers?
Boric Acid and Sodium Hydroxide are used as buffers.
What is the role of a restrainer in developer constituents?
A restrainer improves selectivity and prevents the development of fog.
What are common restrainer agents?
Common restrainers include Potassium Bromide and Benzotriazole.
What is the function of a preservative in developer constituents?
A preservative minimizes aerial oxidation of developing agents.
What are common preservative agents?
Common preservatives include Potassium Metabisulfite and Sodium Sulfite.
What are methods of reducing aerial oxidation?
Methods include high preservative levels, floating lids, closely fitting rollers, and deep narrow tanks.
What is the function of a sequestering agent?
A sequestering agent chelates and helps prevent oxidation.
What is a common sequestering agent?
A common sequestering agent is EDTA Sodium Salt.
