PROCESSING OF LATENT IMAGE Flashcards
What are the systems of film processing?
manual
automatic
daylight
What are the chemical components of processing the latent image?
Developer
Rinsing
Fixer
What are the protective measures when mixing solutions
Wear a mask
Waer nitrile gloves
Wear protective glasses
What are the 2 types of image processing?
Manual and Automatic
This type of processing is used for the advantage of a longer archival property
Manual processing
What are the results of manual processing?
Inconsistency and creation of wet mess
Another name for manual processing
Hand Processing
Required time and space for manual processing
requires 1 hour and excessive amounts of space
Sequence of events in the processing (IN ORDER)
Wetting Developing Rinsing Fixing Washing Drying
This swells the emulsion to permit subsequent chemical penetration
Wetting
Required time for wetting in the manual and automatic processing?
M - 15 secs
A - none
This process produces a visible image from the latent image
Developing
Required time for developing in the manual and automatic processing?
M - 5 mins
A - 22 secs
This stops the development process and removes the excess development from the film
Rinsing
2 kinds of rinsing
Stop bath and Watery
In the stop bath, _______ solution of ______ is mathematical neutralizes the developer
1%, acetic acid
This relies on water to rinse & remove excess developer
Water bath
Required time for stop bath and water bath in the manual and automatic processing?
Stop bath: 30 secs (M) and none (A)
Water bath: 30 secs (M) and none (A)
What is fixing?
It removes the unexposed and underdeveloped silver halide crystals from the film emulsion and also hardens the gelatin
Required time for fixing in the manual and automatic processing?
10 mins (M) and 22 secs (A)
What’s the purpose of washing?
Removes residual from the emulsion surface and excess chemicals unwanted to the film
Required time for washing in the manual and automatic processing?
20 mins (M) and 20 secs (A)
Purpose of drying
Removes water and prepares radiograph for viewing
Required time for drying in the manual and automatic processing?
30 mins (M) and 26 secs (A)
This prepares the film for viewing and storage
drying
2 ways of drying a film
By electric drier/exposure to room air
What is the total time to process one film during manual processing?
65 m and 30 secs
this softens the gelatin and develops the latent image
developer
2 chemicals under the developing agent and their functions
Phenidone - produces shades of grey
Hydroquinone - produces shades of black
Another name of developing agent
reducing agent
This helps swell gelatin and it produces alkalinity controls pH
Activator
Chemical/s under the activator
Sodium Carbonate
Another name for activator
accelerator
This is an ani-fog agent and protects unexposed crystals from chemical
Restrainer
Chemical/s under restrainer
Potassium Bromide and Potassium Iodide
This controls the oxidation; it maintains balance among developer components
preservative
Chemicals under preservative
sodium sulfite
This controls the emulsion swelling and enhances archival property
hardener
Chemical/s under hardener
glutaraldehyde
This removes metallic impurities and stabilizes the developing agent
sequestering agent
Chemical/s under sequestering agent
chelates
This dissolves the chemicals for use
Solvent
Chemical/s under solvent
water
This neutralizes the developer and stops its action; it also buffers the solution
activator (fixer)
Another name for activator
acidifier
Chemical/s under activator
acetic acid
This removes the undeveloped silver bromine from the emulsion to prevent further blackening
Fixing agent
Another word for fixing agent
clearing agent
Chemical/s under fixing agent
Ammonium thiosulfate and Sodium thiosulfate
This stiffens and shrinks the emulsion
Hardener (fixer)
Chemical/s under the hardener
Potassium Alum
Aluminum Chloride
Chromium Alum
This maintains a chemical balance and is used to prevent deterioration of the clearing agent
Preservative (fixer)
Chemical/s under preservative
Sodium sulfite
This maintains proper pH
Buffer
Chemical/s under buffer
Acetate
This removes the aluminum ions
Sequestering agent (fixer)
Chemical/s under the fixer sequestering agent
Boric acids and salts
This dissolves other components
solvent (fixer)
Chemical/s under fixer solvent
water
another term for automatic processing
dry-to-dry processing
When was the automatic processor first made available?
The 1950s
Who made/designed the first unit of an Automatic processor?
Eastman Kodak Company
The first unit of automatic processor required a time of ______ in processing films
excess of 7 minutes
Today, the processing times are reduced to as little as _____
45 seconds
What are the 5 principal components of an automatic processor
Transport Recirculation Replenishment Wash Dryer
This moves the film through the
processor through a series
of rollers
Transport system
What are the different parts of the transport system?
Roller, Transport racks, drive motor
What are the two subsystems of the transport system?
Turn-around system
Cross-over system
Difference between turn-over and cross-over systems?
T: turns the film around the bottom of the tanks
C: located at the top of the tank; allows the film to be moved to the next tank
These are special devices that guide the
film to change direction. These are also curved devices with small ridges that may cause a processing artifact
Guide shoes
It squeezes the excess developer from the wet film
emulsion before it moves to the fixer solution
Squeegee Assembly
What is the speed at which the film must move through the processor?
The speed must remain constant
This agitates the solution and helps maintain the temperature
Transport system
Its purpose is to provide continuous mixing of
the chemicals
Recirculation system
Parts of the recirculation system
Filter
Thermostat
Heater
This part of the recirculation system serves to remove debris and other substances that may fall into the tanks
Filter
This is one of the key elements to the successful use of an automatic processor
Replenishment Rate
What are the replenishment rates for a developer and fixer?
Developer 60-70 ml
Fixer 100-110 ml
for every 35 cm (14 inches) of the film
Its function is a to add solutions to the developer and fixer tanks as each piece of x-ray film move through the system
Replenishment system
It serves to maintain the volume and strength of
the solutions in the developer & fixer tanks
Replenishment system
This activates the pump that sends replenisher solution into the tank as the film moves between the rollers of the transport system
Microswitch
What are the subsystems of the replenishment system?
Over-replenishment
Slight under replenishment
Under replenishment
Adequate Replenishment
It may result in a decrease in contrast and density on the film
Over-replenishment
This can result in an increase in contrast
Slight under replenishment
Contributes to a loss of both contrast and density
Under replenishment
It keeps the chemical activity stable and helps
prevent tackiness of the film
Adequate replenishment
It is necessary to remove excess chemicals to prevent deterioration of the film
Wash system
The finished film must only contain _______
developed silver crystals
Water flows around the chemical tanks to help ______
control the temperature
It blows hot air across the surface of the film to enhance the drying of the surface
Dryer System
Air temperature of the dryer
110 to 120°F
Air is continually dried by a what?
dehumidifier
Most of the dry hot air is ________, however, the dryer must be ______
recirculated, vented
How do you maintain the processor unit in automatic processing?
- Routine checks and cleaning of the transport rollers
- Careful examination and adjustment of the guide shoes
- Cleaning and replacing filters
What are the daily maintenance procedures?
- Temperature readings
- Water flow
- Drainage
- Filters
- Replenishment rate
- Microswitch control
It operates without the need for a conventional darkroom
Daylight Processing
What kind of cassettes are used in daylight processing?
Special Cassettes
What is the advantage of using daylight processing?
Removal, loading, and moving of film without interaction by staff personnel
What is the disadvantage of using daylight processing?
- Costly than a standard processor
- Mechanical breakdowns
- Artifacts caused by mechanical devices