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RAD Ch. 6 Vocab
Rad Ch. 6 Vocab
Question | Answer |
---|---|
Anatomically Programmed Radiography (APR) | A computerized control that is programmable so that exposure factors from a conventional technique chart can be made available from within the computer. |
Automatic Exposure Control (AEC) | An electronic circuit within the x-ray machine that automatically terminates the exposure time when a certain quantity of radiation has been detected at the IR. |
Autotransformer | Its primary purpose is to vary the voltage to the primary side of the step-up transformer. |
Back-up Time | A manually set time that insures that an exposure will be terminated should the automatic exposure control fail. |
Control Console | The unit where the operator sets all of the exposure techniques, such as kilovolts peak, milliamperes, and exposure time. |
Diode | An electronic device that permits current to flow in one direction only. |
Electric ground | A device that absorbs or drains off excess electrical charges, resulting in zero electrical potential. |
Exposure timer | A device that terminates the exposure by opening a switch after a preset time has elapsed. |
Exposure switch | Closes the circuit, which allows current flow, creating voltage across the x-ray tube. |
Electronic timer | The most accurate form of manually set timers where exposure times are expressed in decimals; Designed for use with three-phase and high-frequency generators. |
Full-wave rectification | The redirection of the second half of the electrical cycle so that current will flow in the same direction during both halves of the cycle. |
Half-wave rectification | Negative voltage is suppressed so that the flow of current is only utilized during the positive flow of alternating current. |
Heat units (HU) | Determined by multiplying the MAS by the KVp; Used to calculate cooling times. |
High-frequency x-ray generator | These units employ special Ainverter circuits that convert rectified AC into a series of square pulses. |
Ionization Chamber | One type of automated exposure control where an enclosed volume of dry air is connected into a circuit; Located between the patient and the IR. |