Midterm | Processing Chemistry Flashcards
Refers to the series of steps that converts the latent image into the visible radiographic image.
FILM PROCESSING
The exposed crystal becomes (1) that is visible (2)
- black grain
- microscopically
In handing the different processing chemistry, these should be put into mind
- Wear a proper mask that reduces inhalation of fumes.
- Wear nitrile gloves (do not use surgical gloves)
- Wear protective glasses (prevent chemical splashing into the eyes)
Standrard value for pH level for all solutions
0-14
Standard value for pH level for Developer
10-10.5
Standrad value for pH level for Fixer
4-4.5
Standard value for Developer Temperature
95-100°F or 35-38°C
Standard value for Fixer Temperature
appx 94°F or appx 34°C
Standard value for Water Temperature
appx 94°F or appx 34°C
Standard value for Automatic processor; Dryer temperature
120-150°F (2.5kW)
AUTOMATIC PROCESSOR REPLENISHMENT RATE FOR DEVELOPER
60-70 mL or cc / 14” film
AUTOMATIC PROCESSOR REPLENISHMENT RATE FOR FIXER
100-110 mL or cc / 14” film
Processing Sequence and appx time (Manual)
Wetting: 15s
Developing: 5mins
Rinsing in stop bath: 30s
Fixing: 15 mins
Washing: 20mins
Drying: 30 mins
Processing Sequence and appx time (Automatic)
Developing: 22s
Fixing: 22s
Washing: 20s
Drying: 16s
The first step in the processing sequence involves wetting the film to (1), so the subsequent chemical baths can (2).
- swell the emulsion
- reach all parts of the emulsion uniformly
In automatic processing, this step is omitted and the agent used is incorporated into the next step
wetting
Universal solvent
Water
A liquid into which various solids and powders can be dissolved
Solvent
For the chemicals to penetrate the emulsion, the radiograph must first be treated by a/n (1) which is water, and it penetrates the (2) of the emulsion, causing it to swell.
- wetting agent
- gelatin
Principal action of developing
To change the silver ions of exposed crystals into metallic silver, which produces a visible image from the latent image.
DEVELOPING
For the (1) to be changed to (2), a/n (3) must be supplied to the (4).
- ionic silver
- metallic silver
- electron
- silver ion
Process wherein an electron is given up by a chemical (developing agent), to neutralize a positive ion
REDUCTION
In the process of reduction, the (1) is said to be reduced to (2), and the chemical responsible for this is called (3).
- silver ion
- metallic silver
- reducing agent
A reaction that produces an electron.
Oxidation
Oxidation and reduction occur simultaneously and are called —
REDOX REACTIONS
Components of the developer and chemicals used
- Developing agent (Phenidone and Hydroquinone)
- Activator (Sodium carbonate)
- Restrainer (Potassium bromide)
- Preservative (Sodium sulfite)
- Hardener (Glutaraldehyde)
- Sequestering agent (Chelates)
- Solvent (Water)
Reducing agent; produces shades of gray rapidly
Phenidone (Developing agent)
Reducing agent; produces black tones slowly
Hydroquinone (Developing agent)