click below
click below
Normal Size Small Size show me how
film processing-DENH
| Question | Answer |
|---|---|
| What appears on radiographs after being exposed? | latent image |
| What does exposure entail? | x-ray beam, density of object, and sliver bromide crystals |
| What occurs to the silver bromide after exposure? | they are energized from the radiation |
| What are the 3 components of processing? | developer, fixer, and washing |
| What does developer do to film? | softens gel, reduces silver halide crystals by precipitation of silver |
| Which component is acidic and which is alkalinic? | Fixer is acidic and developer is alkalinic |
| what does elon and hydroquinone do? | reduces silver bromide to silver |
| what does sodium carbonate do? | softens gel to allow hydroquinone to reach silver bromide and maintains alkalinity |
| what does potassium bromide do? | prevents chemical fog (sometimes) |
| what does sodium sulfite do? | preservative |
| what is manual developer dependent on? | temperature: if high, decrease processing time; if low, increase processing time |
| What is special about fixer? | it needs to be recycled due to the silver |
| what does sodium thiosulfate do? | removes remaining silver bromide from emulsion |
| what does sodium sulfate do? | prevents decomposition of thiosulfate |
| what does potassium aluminum do? | shrinks/hardens gelatin (emulsion) |
| what does acetic acid do? | maintains acidity |
| If using manual fixer, what needs to happen to the developing time? | double developer time (minimum of 10 min) |
| how long must it stay in the fixer for a wet read? | 3 minutes |
| what can occur if inadequate fixing happens? | brown film |
| what does washing do? | stops developer, remoes developer so fixer is not contaminated |
| if a manual process is used, how long is film washed? | twice as long as it is fixed (minimum 20 min) |
| what can occur if film is overagitated during any of the processes? | removes image from film |
| what is rapid processing used for? | endodontics and post-operative |
| what kind of image is produced using rapid processing? | inferior in density and definition to standard method |
| what are the 4 steps of automatic processing? | developer, fixer, wash, dryer |
| what is standarized processing involve? | solution strength, temp, and time = increased quality control |
| what 3 items need to be recycled? | lead foil, fixer solution, and non-diagnostic radiographs |
| what determines film speed? | size of crystals; larger=faster |
| what occurs due to larger crystals? | decrease definition |
| what is the main advantage of an automatic processor? | standardization |
| as film speed increases, sensitivity _____. | increases, which decreases exposure time |
| what size of film is occlusal? | 4 |
| PROCESSING SLOUTIONS SHOULD BE CHANGED EVERY? | 2-3 WEEKS |
| FILM EXPOSURE TEST UTILIZING A "STEP WEDGE" EVALUATES WHAT? | SOLUTION STRENGTH |
| EXHAUSTED PROCESSING SOLUTION CAN CAUSE WHAT? | FOG |
| WHAT IS THE FASTEST FILM SPEED? | F |
| LIGHT LEAKS IN THE DARKROOM RESULT IN _____ ON THE FILM. | FOG |
| AS SILVER PRECIPITATION INCREASES, FILM BECOMES WHAT? | DARKER/ MORE RADIOLUSCENT |
| SILVER BROMIDE CRYSTALS ON A FILM THAT LIES BEHIND A CROWN RECIEVES HOW MUCH RADIATION? | MINIMAL/LESS |
| A SIMPLE TEST USED TO CHECK THE SAFETY LIGHT IS CALLED? | COIN TEST |
| THE MAIN FUNCTION OF LEAD FOIL IN THE FILM PACKET IS TO WHAT? | ABSORB RADIATION |
| OBJECT MAGN INCREASES WHEN OFD IS? | INCREASED |
| TO COMPENSATE FOR THE DECREASE IN IMAGE SHARPNESS THAT RESULTS FROM INCREASING OFD, WHAT IS INCREASED ALSO? | FFD |
| IMAGE DETAIL IS DEPENDENT IN FILM _____ | SHARPNESS |
| FILM DEFINITION IS AKA? | DETAIL |
| ONE EFFECT OF SECONDARY RADIATION ON FILM IS? | FOG |
| THE FFD OF ____ INCHES PRODUCES THE LEAST AMT OF MAGN | 16 |