title: Constancy of radiation output during diagnostic x-ray expousers.
abstract: Variation in X-ray output and quality during a diagnostic exposure can be undesirable and may result in unnecessary dose to the patient. When significant build-up or decay periods are present errors will arise if factors obtained under steady-state conditions are employed to estimate the exposure. These parameters must be taken into account when calibrating X-ray generators. A variable speed spinning film device and a spectrometry system have been used to measure the variations under fluoroscopic and radiographic conditions for a number of generators. Variations in output due to filament heating, voltage supply and rectification, cable capacity and target pitting have been demonstrated. At low fluoroscopic currents, large surges and long decays have been observed; the significance of these effects is considered.
mesh_terms: D005471:Fluoroscopy; D008722:Methods; D011829:Radiation Dosage; D011859:Radiography / Q000295:instrumentation; D013052:Spectrometry, X-Ray Emission