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16 Cards in this Set
- Front
- Back
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An exposure chart is designed to provide a detailed exposure technique for a material of a given thickness which will produce a what?
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predetermined density with a specific x ray machine and set of parameters
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An exposure chart is sometimes called what?
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constant density chart or technique chart
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What two things that exposure chart parameters consist of?
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variables and constants
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What are the three variables of an exposure chart?
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exposure(given in mAs/mAm), kV ranges and material thickness(predetermined range)
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Where are the constants listed on the exposure chart
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on the legend block
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List the nine constants the are listed in the legend.
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1) type of material 2) type of machine used 3) type and make of film 4) H&D (density produced) 5) MA 6) SFD 7)Quality enhancers if used 8) processing methods 9) type of development
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Why is semi-logarithmic paper used for exposure charts?
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prevents lines from curving back onto each other and allows pertinent info. to be placed in a reduced amount of space
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What are the four ways to construct an exposure chart?
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1) step block 2) step block characteristic curve 3) wedge-tapered 4) wedge and characteristic curve
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Which is the least preferred way to construct an exposure chart?
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step block
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Which is the most accurate way to construct an exposure chart?
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wedge tapered
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What is the math formula used for the wedge characteristic curve?
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(Tan(Angle of the wedge) x D) + t = T
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What is the "D" in the wedge and characteristic curve represent?
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The distance measured on the film from the image of the thin edge to the point the density was measured
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What is the "t" in the wedge and characteristic curve represent?
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Thickness of the thin edge of the wedge which is normally .125"
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Which exposure chart construction method is used in class?
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wedge and characteristic chart
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What are the factors for the selection of film to be used for the exposure chart?
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1) select a film you will use often 2) has good contrast and latitude 3) has a characteristic curve available for it
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What four density are measured to produce the the characteristic curve?
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1.6, 1.8, 2.0, 2.2
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