Chapter 7 Notes Flashcards
the single function of an AEC is to
eliminate the need for the radiographer to set an exposure time
when using an AEC, it is critical that
the location of the ionization chamber be determined and that the precise positioning of tissue over that location be acheived
AECs are usually used in a _____ configuration
three-chamber
most common relationship of the three chamber configuration
center chamber at the center of the IR with right and left chambers slightly higher
when more than one ionization chamber is selected
signals from the cells are sent from all the selected chambers to average the voltages received
typical AEC density control labels are
-3, -2, -1, 0, 1, 2, 3 or 1/4, N, 1 1/4, 1 1/2
backup times should be set at what percent of the expected manual technique time
150%
AEC was introduced by and when
Russell H. Morgan; 1942
exposure control scale increments indicate
a 25% change
“0” for the receptor exposure controls indicates what
normal density
AEC utilization is not a substitute for
optimum patient positioning
clipping a detector chamber due to tight collimation will do what to the image
overexpose the image
what is the minimum response time
exposure time required for detector to sense radiation and terminate exposure
what is the typical minimum response time
0.001 second
federal law requires automatic termination at
600 mAs when working above 50 kVp
