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.
Its primary purpose is to vary the voltage to the primary side of the step-up transformer.
A manually set time that insures that an exposure will be terminated should the automatic exposure control fail.
The unit where the operator sets all of the exposure techniques, such as kilovolts peak, milliampheres, and exposure time.
An electronic device that permits current to flow in one direction only.
A device that absorbs or "drains off" excess electrical charges, resulting in zero electrical potential.
A device that terminates the exposure by opening a switch after a preset time has elapsed.
Closes the circuit, which allows current flow, creating voltage across the x-ray tube.
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.
Redirecting the second half of the electrical cycle so that current will flow in the same direction during both halves of the cycle.
Negative voltage is suppressed so that the flow of current is only utilized during the positive flow o 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 "inverter circuits" that convert rectified AC into a series of square pulses.
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.