Study RAD Film 6.5 - 6.8 Flash Cards

 
Pile Management Card
RAD Film 6.5 - 6.8

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what is a source of light that will not fog films and still provide adequate illumination under processing conditons
safelight filters
what removes the unexposed and undeveloped silver halide crystals and hardens the emulsion
fixing chemicals
what happens when the screen speed is highered
better sharpness of the image and detail is impaired
where is the light directed to from an indirect safelight
the ceiling or walls
what are the two types of fixing agents and their description
sodium thiosulfate-powdered fixer
ammonium thiosulfate-liquid fixer
what is agent that removes undeveloped silver bromide from the emulsion
fixing agent
what is also called the stop bath which neutralizes the developement
activator
what is the solvent that dissolves all chemicals
water
what is the sequestering agent that removes metallic impurities
chelates
what is the hardner that controls emulsion swelling and aids in archival quality
glutaraldehyde
what is the preservative agent that controls oxidation and maintains chemical balance among the developer
sodium sulfite
what is the reducing agent that is the principal component of the developing chemical. It reduces black tones slowly and can only act in an alkaline medium
hydroquinone
what is the restrainer agent that keeps unexposed crystals from being chemically attacked w/o preventing the action of the developer on the exposed grains
potassium bromide
what accelerator agent helps to swell emulsion and enhances the actions of the developing agents/ very caustic
sodium carbonate
what is the reducing agent that produces shades more rapidly and is used in automatic processing
phenidone
what is the reducing agent that produces a basic gray image used in manual processing
metol
what are the 3 reducing agents
metol
phenidone
hydroquinone
what are types of developing chemicals
reducing agents
accelerator agents
restrainer agent
preservative agent
hardner
sequestering agent
solvent
what converts latent image to a visible image
developing chemicals
what is the drying time for a screen after it's been washed
1/2 hour standing half open on it's side
what do you use to clean screens
water and bland soap
how will foreign bodies on the screen effect the radiograph
cause marks and white shadows
on a gradient screen which end is faster, which end is slower and what body parts match up with them
the thicker end is faster (thicker body part) and the thinner end is slower (smaller body part)
how are gradient screens made
by gradually increasing the thickness of the emulsion from one end to another over the length of the screen
what do special screens do
gradually increase speed form one end to another
what is another term for gradient screens
special screens
what is it when light from one screen passes through the film base to the opposite sides of the emulsion and penumbral divergence is increased and detail is reduced
screen crossover
the screens ability to produce density with a given exposure to xrays
screen speed
what is the atomic numbers of rare earth
57-71
what color dye is commonly used in detail screens
yellow
what does adding a colored dye to the emulsion do
effective way to increase sharpness
higher absorption and conversion efficiency is obtained by what
using rare earth screens rather than increasing emulsion thickness
what are causes for poor screen-film contact
warped cassette
cracked or twisted cassette frame
loose hinges or spring latches
foriegn bodies
rough handeling and dropping of the cassette
what happens to the image when poor or uneven contact causes the flourescent light to diffuse
blurring
what is crucial for image sharpness and detail
closeness of the screens
what gives xray film a higher inherent contrast
light
screen output is dependent on what
kVp
direct exposure is bad for what reason
longer exposure time to the patient
direct exposure will allow what and lower what
allow better detail
lower image contrast
higher contrast in the image is obtained by utilizing what
screen cassettes
what type of screen shows virtually no variation with speed and changes in kV
calcium tungstate
what does the percentage drop to with phosphorus when reduced to 70 kV
75%
screen speed peaks at what kV with phosphorus
100kV
when room temperature rises what happens to the film and screen speed
film speed increases
screen speed decreases
what are the types of extrinsic factors for intensifying screens
temperature and kV (kilovoltage)
a faster speed screen will do what to the image
decrease sharpness
what will increase the speed most effectively of the phosphorus active layer of a screen
thickening of the active layer
what are the four intrinsic factors
phosphor
thickness of active layer
size of phosphor crystals
reflectance of backing
what are the two factors that effect screen efficiency
intrinsic and extrinsic factors
what portion of the spectrum do rare earth elements emit wavelengths in
green
what are the two most common rare earth elements
lanthanium & gadolinium
which is the most used type of active layer
rare earth
what are the two types of active layers that make up the emulsion
calcium tungslate & rare earth
what is another name for screen lag
ghost image
what is the phosphorescence of an intensifying screen whereby light continues to be emitted after xray stimulus has ceased
Screen lag
what are the things that influences the screen efficiency
-ability to absorb xray
-convert xray into light rays
-emit the light produced out of the emulsion and to the film
what is the ability of a screen to produce a density
screen efficiency
what is a common way to increase screen speed
thicken the emulsion
what happens if you increase screen speed
the more density will produce at a given exposure
what is the term that refers to a screen's ability to produce density with a given exposure to xray
screen speed
what is it called if the phosphor continues to emit light after stimulation. it is the second type of luminescence
phosphorescence
what is it when visible light is emitted only when the phosphor is stimulated
flourescence
what is emitted visible light called
luminescence
any material that emits light as a direct result of some outside excitation or stimulation
luminesce
what is the thickness of the active layer
.01mm
what is the purpose of the base
serves principally as the mechanical support for the active layer
how thick is the base
1mm
what is the layer farthest from the film
Base
what is the purpose of the phosphor
convert the energy of the xray beam into visible light
what is the active layer of the xray intensifying screen
phosphor
processed films can not be stored at a temperature exceeding
70
unprocessed films should not be stored with temperatures greater than what
68 degrees f
20 degrees c
what are some examples of film mistreatment
heat
light
xray
chemicals/fumes
pressure
rolling
bending
what can be added to the room to restore moisture in the air
humidifier
warning signs for possible static eletrical problems should go off when the humidity gets to
40%
the loading bench should be what to prevent the build up of electric charges
grounded
what is the problem with static electric discharge when refrencing film developement
it emits a visible light which is capable of fogging film
what are the factors that make an enviroment favorable for static electricity
when two surfaces are non conductors and humidity is high
what may occur when there is a difference in electrical potential energy between two oppositely charged bodies, or between two bodies having like charges of different sizes
static electricity
what may occur when two dissimiliar surfaces are brought together and later seperated
static electricity
what wattage should a safelight not exceed
15 watts
what type of filter uses blue and green sensitive film
GBX
what type of safelight filter is GS-1 used for
green sensitive ortho-g film
what type of safelight filter is Wratten 6B used for
blue-violet sensitive
what are the three safelight filters
Wratten 6B, GS-1, GBX
what is the optimum distance for a direct safelight
6 ft
a direct safelight should be no less than how far from the work bench
3 ft
what are the two types of safelights
direct and indirect
what is the transition period from refrigeration to normal temperature before use for xray film
24 - 48 hours
film is able to be stored for a year or more if the film is maintained at what temperature
50 degrees
what does pressure do to the film
marks and artifacts
fumes does what to the film
increases fog
x radiation does what to the film
increases fog
films should be stored in what type of enviroment
cool, dry place
what is the effects of heat on film
increases fogging
what is the recomended way to open a foil xray film bag
from the center first stripping the bag away to each side
what could rapid movements cause when opening a package of xray film which could damage the film
static electricity and pressure artifacts
what is the humidity sealed into the xray film packaging
50%
how much is the quantity of each unit of packed xray film
100 per unit
what does the xray packing protect the film from
light and moisture
xray film is packed in what
hermetically sealed foil and paper wrappings
films are very sensitive to what
mistreatment of any kind
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