Processing the latent image Flashcards
test 1 review part 2
steps of manual processing
1) films immersed in a developer for 5 minutes
2) then immersed in a stop bath tank
3) followed by immersion in a fixing solution
4) then washed in running water and hung to drip dry
How long did the manual process take in order for for image to be fully dry and ready to read?
1 hour
First available automatic processing was by _____ in _____. how many films was it able to process for an hour? How long was the total cycle time?
pako, 1942
120 films per an hour
total cycle time- 40min
The first roller transport system was available in ____. how long was the system and how long did it take to process a radiograph?
1956
10 ft long and it took 6 minutes
90 second rapid processor was available in ____.
1965 by eastman kodak
Purpose of the developer
to change silver ions of the exposed crystals into metallic silver
Hydroquinone
DEVELOPER, slowly reduces silver, blackest shades (part of developer)
Phenidone
DEVELOPER rapidly reduces silver, lighter shades of gray, enhances fine detail (part of developer)
Sodium Carbonate
ACTIVATOR, helps swell gelatin; produces alkalinity; controls pH (concentration of hydrogen) (part of developer)
Buffering agents
sodium carbonate and sodium hydroxide; controls pH; caustic (burns skin) alkali compound (part of developer)
Restrainer agents
Potassium bromide and Potassium Iodide; anti fog agent; protects unexposed crystals from chemicals “attack” (part of developer)
Sodium Sulfite
PRESERVATIVE; controls oxidation; maintains balance among developer components (part of developer)
Glutaraldehyde
HARDENER; tanning agent; controls emulsion swelling and enhances archival quality (part of developer)
Chelates
SEQUESTERING AGENT; removes metallic impurities; stabilizes developing agent (part of developer)
If film comes out damp it is a depletion of ________ in the solution
Glutaraldehyde
It takes _____ of fixer to contaminate the developer
0.1%
Water
SOLVENT; dissolves chemicals for use (part of developer)
ACTIVATOR; neutralizes the developer and stops its action (part of fixer)
Acetic Acid
FIXING AGENT; removes undeveloped silver bromine from emulsion (part of fixer)
Ammonium thiosulfate aka hypoagent or clearing agent
Milky appearance means ________ _______
incomplete fixing
Image discolors to brown
Hypo retention
HARDENER; stiffens and shrinks emulsion; ensure proper transport (part of fixer)
Potassium alum
PRESERVATIVE; maintains chemical balance (part of fixer)
sodium sulfide
BUFFER; maintains proper pH (part of fixer)
Acetate
SOLVENT; dissolves other components (part of fixer)
water
Developing process- Reduction
electron is given up to neutralize a positive ion
Developing process-oxidation
produces electron
Developing process- Redox action
reduction and oxidation occurs simultaneously
Since air oxides the chemicals as the level of chemicals reduce, what can be done to control oxidation?
Putting foam balls to control levels
development process can be affected by _____ _____ and ______.
time, temperature, and concentration
contamination
destroys ability of the reducing agents; low contrast, extremely gray
most common cause of contamination
splashing fixer into the developer tank
fixing process
removes unexposed and undeveloped crystals from the emulsion
what is the temperature range for the dryer?
120 to 150 degrees F
How long is the dry to drop time?
90 seconds
transport system includes:
feed tray, entrance rollers, turnaround assembly, crossover rack
Developer temperature is maintained at
95F or 33-35C
wash water is how many degrees less than the developer?
3 or 5 degrees F
volume based replenishment system
based on the usage when replenished
flood based replenishment system
low volume settings, floods the tank and then settles them back out
what side of the film should always be against the side rail?
shorter side
purpose of dryer system
extracts all residual moisture from the finished radio graph
picks up particles that can cause artifacts if it is left damp
room air low in humidity and free of dust
purpose of Agitation
continually mix processing chemicals, maintains constant temperature, aid exposure of emulsion to chemicals
Rapid processing
30 seconds, more concentrated chemicals, higher developer and fixer temperatures
used in angiography, special procedures surgery or ED
Extended processing
mammography, 3 minute processing time, patient does is lower
Daylight processing
disappearing darkrooms,
- insert cassette into processor and film is automatically extracted
- Reloaded with unexposed film and then is released by the system
Dry processing
use without wet chemistry
Two other types of alternating processing methods
photothermographic (PTG) and Thermographic (TG)
entrance of darkroom
single door, interlocking doors or a revolving doors
dark room disease
from the chemicals
photographic industry consumes ____% of worldwide
30
how much of the purchased price of film can be recovered.
10%
________ million more ounces of silver are consumed than produced
120
bans placing toxic substances in public waterways and sewer systems
water control act of 1972
requires that available devices must be used to remove toxic substances from waste water
resource conservation/ hazardous waste act of 1976
requires the best available methods be used to remove toxic substances from waste water
clean control act of 1984
contains many guidelines affecting film processing affecting film processing and silver recovery methods
resource conservation and recovery act of 1987
requires the best available devices must be used to remove toxic substances from waste water
clean water act of 1984
contains many guidelines affecting film processing and silver recovery
resource conservation and recovery act of 1987
metallic replacement method
simplest and least expensive method
most widely used
little maintenance
95% of recoverable silver is removed
disadvantages of metallic replacement method
not as efficient, form of silver sludge, unit replaced upon each expenditure in recovery process,
