Noninvasive x-ray tube current measurement.
A clamp-on current probe utilizing the Hall effect was used to determine x-ray tube current. This noninvasive technique was compared to two other methods of mA measurement: the Machlett Dynalyzer and the mR/mAs linearity method. Three diagnostic x-ray units were used in the comparison; two modern three-phase rooms and one 25 year old single-phase room. The Dynalyzer and current probe measurements agreed to within +/- 3% and showed mA miscalibration at several technique settings. The mR/mAs linearity method failed to detect any miscalibration. One disadvantage of using the current probe is its susceptibility to electronic noise when making measurements of tube current below 100 mA. These results justify the use of the current probe in routine quality control calibration checks.
D004869:Equipment Safety; D011786:Quality Control; D011859:Radiography / Q000295:instrumentation*