Film Processing Flashcards
What is reduction?
Halide portion of the exposed, energized, silver halide crystal is removed
What is the chemical reaction that occurs during film processing?
Selective Reduction
Reduction of energized, exposed silver halide crystals into black metallic silver, while the unenergized, unexposed silver halide crystals are removed from the film
What does developer do?
distinguishes between exposed and unexposed silver halide crystals
reduces the exposed silver to black metallic silver and creates dark or black areas on the radiograph
What does fixer do?
Removes the unexposed silver halide crystals and creates white or clear areas on the radiograph
What are the 4 basic ingredients in film developer?
Hydroquinone and Elon(developing agents) Sodium sulfite (preservative) Sodium carbonate (accelerator) Potassium bromide (Restrainer)
4 Basic ingredients in fixer
Sodium thiosulfate or ammonium thiosulfate (fixing agent)
Sodium sulfite (preservative)
Potassium alum (hardening agent)
Acetic or sulfuric acid (acidifier)
WHat is the purpose of a developing agent?
To reduce the exposed silver halide crystals chemically to black metallic silver
What is the purpose of the preservative?
To prevent the developer from oxidizing when exposed to air
To prevent chemical deterioration of the fixing agent
What is the purpose of the accelerator?
To activate the developing agents
Only active in an alkaline environment
What is the purpose of restrainer?
To control the developer and prevent it from developing the exposed AND unexposed halide crystals
What is the purpose of fixing agent?
To remove or clear all unexposed and undeveloped silver halide crystals from the film emulsion
What is the purpose of the hardening agent?
To harden and shrink the gelatin in the film emulsion after the accelerator in the developing solution has softened it
What is the purpose of the acidifier?
To neutralize the alkaline developer
What is the optimal temperature for developer?
68 degrees farenheight
What is a replenisher solution?
Super concentrated solution that is added to the processing solutions to compensate for loss of volume and strength that results fro oxidation
