Rad last test
Card Set Information
Rad last test
Film developer and errors
What is the latent image and when is it obtained?
The image is not visible before processing and it is obtained after the film is developed.
If the developer temperature goes up then the development time goes _____.
How long must film be fixed?
2X developing time (minimum of 10 minutes)
What is the optimum time and temperature for manual processing
5 minutes at 68 degrees
What two things does the developer do?
Softens and swells the emulsion
Reduces the exposed silver halide crystals into black metallic silver
What does the rinse after development do?
What developer chemical is called the developer agent (reducing agent) that is sensitive to temperature?
What is the developer chemical that is called the developer agent (reducing agent) that is
sensitive to temperature?
What chemical is called the activator?
What chemical is the preservative and is in both solutions?
What three things does the fixer do?
Stops further development
Removes unexposed (undeveloped) crystals
Shrinks and hardens the emulsion back up
What chemical shrinks and hardens the emulsion?
What is the fixing or clearing agent?
Sodium thiosulfate or Sodium hyposulfate
In which tank should the thermometer be placed?
How long should films be in the final wash?
20-30 minutes with manual
What safelight can be used with a pan and other intra/extra oral films?
What safelight can be used for intraoral films only?
How far should the safelight be at a minimum from the counter?
What three things determine the safety of the safelight?
7-15 watt bulb
4 feet away distance
Type of filter
What is the sign of an exhausted developer?
Thin and faded image
What is the sign of an exhausted fixer?
milkly, sticky residue
Black marks on film can be caused by what?
Fingernail indentations, bending, static, developer splashes
Clear or light spots or marks on a radiograph are due to what?
Fixer splashes, air bubbles, scratched emulsion, lead apron artifact.
A herringbone pattern appear on a film if it is what?
Placed in the oral cavity backwards
Placing a film in the fixer first results in a _____ film.
If a film is not immersed in the developer completely and then is immersed completely in the fixer what would the result be?
Clear area where it was not immersed
A film is immersed completely in the developer but not the fixer what would the result be?
A dark area where it was not immersed
Radiographs are caused by all except: temp of developer too cool, insufficient developing time, exhausted developer solution, and overexposure
What causes film fog?
Scatter radiation, light leaks, unsafe safelight
What is the wrinkled appearance that occurs when a film goes from extreme temp to another?
What is the recommended method for manually developing film?
What does the coin test monitor?
: no image of coin
What does the stepwedge test monitor?
Solutions and Machines
What does the wire mesh test monitor?
What determines the life of the solutions?
Accuracy in prep
Freshness of solution
Cleaniness of tanks
Exposure to light
Temp of solutions
Size of film
Where do you find information on storage, usage, and emptying?
When replenishing solutions how much is added approximately?
1 cup of developer and fixer
Is there a rinse step in automatic film processing?
Approximately how often should solutions be changed?
Once a week
Can the same solutions be used in both manual and automatic processing?
What happens to film quality if not washed or fixed long enough?
Film turns yellowish brown
Film totally exposed to white light before developing will be what?
Film that is unexposed will appear _____ after processing.
A film that does not come into contact with the solutions will emerge _____.
What causes dark stains?
A thin or light image on an x-ray film can be produced by what?
Cold developing solution
What indicates that a radiograph was overexposured?