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Term Definition
what is AEC referred to as in practice phototiming
modern X-ray equipment uses ______ rather than photocells ionization chambers
when was AEC introduced and by who 1942 by Russell H. Morgan
an AEC device is a _____ photocell
photocells are either an ionization chamber or a _____ photomultiplier tube
where are photocells placed near the bucky
what does the photocell determine the length of the X-ray exposure
exit radiation from the patient hits the _____ and the current produces inside the photocell charges the X-ray _____ photocell, timer
when the ____ receives a predetermined amount of charge from the photocell, what happens to the X-ray exposure xray timer, it is stopped
the predetermined amount of charge is set so that the densities of the image will fall between what range above base plus fog .25-2.0
what does the AEC eliminate the need for the radiographer to select a time and therefore mAs
because AEC takes care of selecting a timer/mAs, what does the tech set instead kvp to control contrast and the detectors activated to control density
AEC provides a diagnostic quality image only for structures positioned where directly above the ionization chambers
what is extremely crucial to do when using AEC and why positioning the part correctly is crucial because the target tissue must match up to the ion chamber in order to be useful
how many ion chambers can be activated 1-3
what receives and averages the signal from each chamber operational amplifier
when does the exposure terminated when the intensity is achieved
what permits the adjustment of intensity if necessary to terminate the exposure and varies the length of the exposure time density controls
what number represents normal density 0
what number represents a 25% decrease in relative exposure -1
what number represents a 50% decrease in relative exposure -2
what number represents a 25% increase in relative exposure +1
what number represents a 50% increase in relative exposure +2
poor positioning skills can result in an increase in what when using AEC repeats
subject density and contrast problems occur when an unexpected density is present or an expected density is absent like what fluid in lungs, emphysema, osteoporosis
what should be avoided when collimating and using AEC collimating too close to the chambers because too close collimation within an activated chamber will result in an overexposed image
the backup time is what percent of the expected time 150%
the federal law requires automatic termination at what when working above 50 kvp 600 mAs
what is a computerized technique chart that uses AEC capabilities and has a manual override automatically programmed radiography
manual technique always provides what a repeatable exposure
while manual technique always provides a repeatable exposure, AEC leaves the tech doing what guessing
care must be used when an activated sensor is not completely covered by the tissue and this requires ____ techniques not advised by inexperienced radiographers creative
the larger the patient the ____ the exposure time longer
photocells are usually in groups of ____ 3
the backup timer is set ____ the expected exposure time above
if the backup timer is set below the expected exposure time what happens the exposure will be stopped too early
is the backup timer is set below the expected exposure time what will the image look like too light
if the kvp is changed what will the AEC compensate for it will compensate with an adjustment in exposure time to adjust density

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