Quality assurance 2 Flashcards
(35 cards)
what causes a pale or weak image? 5
Incorrect exposure selected -> not enough radiation -> underexposed
Film not in developing tank long enough
Exhausted developer
Chemicals not diluted correctly
Temperature of developer too low
how to prevent a pale/weak image? 5
Following quality assurance programme
Sensitometry testing and routine processor maintenance
Check x-ray tube output
Select correct exposure output
Top up developer when required
what has caused the speckled areas on the phosphor plate?
underexposed areas
this is a pale/weak image
what are these dark areas called?
fogging
what causes fogging? 2
Light leakage from incorrect storage
Light leakage into glovebox of processor from incorrect handling
- Leakage into glove box of processor
how is fogging prevented? 4
○ Quality assurance programme
○ Coin test in glove box
○ Correct storage of film
Staff appropriately trained
this is an example of a dark image
what causes a dark image? 2
Too high exposure
Processing fault
- Film too long in developer tank
- Temperature of developer too high
- Developer not diluted enough
how is dark image prevented? 4
Quality assurance programme
Routine maintenance of processor
Check developer temperature regularly
Staff training
this is an example of green/yellow tinted film
what causes green/yellow tinted film?
Insufficient fixing during processing
- Time
- Temperature
- Dilution
how is green/yellow tinted film prevented?
Processor maintenance
Topping up fixer when required
patterns on the image can be caused by what? 3
chemicals
static electricity
damaged pixels on solid stated sensor
what causes this patterning?
Chemicals not properly washed from film during processing
Dark spots from developer splashed
Clear spots from fixer splashes
how is chemical patterning prevented?
processor maintenance
what causes this black patterning?
static electricity from Film pulled quickly from packet when atmosphere is dry
how is static electricity patterning prevented?
Darkroom is well ventilated
Correct storage and handling
what has caused this dark patterning of the lower left corner?
damaged pixels on solid state sensor
what has caused this white line artefact on phosphor plate image?
Speck of dust on sensor on the processing tower blocking data transfer from a line of pixels
how is white line artefact from dust prevented?
Careful handling
Regular maintenance
Phosphor plates and sensors scanned monthly for damage
notice the scratches and delamination of sides of this phosphor plate image
what has caused the phosphor plates to not function properly creating this image?
Extreme temperature change
phosphor plate damage
