DETECTOR RESPONSE AND EXPOSURE CONTROL OF THE RADIO VISIOGRAPHY SYSTEM (RVG 32000 ZHR)

The RadioVisioGraphy system (RVG 32000 ZHR) was studied with respect t o some physical properties including the precision and linearity of th e exposure control and the detector response to x-rays. The x-ray unit was found to yield repetitive exposures that are precisely controlled by the CCX timer. A ''preheat'' and an ''after exposure'' period were noticed, and their resulting x-ray exposures were measured. Two RVG d etectors were compared for their responses with x-rays. The difference s between the detectors were insignificant. However, inhomogeneous det ector responses were found in both of the detectors; with the same exp osure, the central parts of the detectors yielded lower pixel values t han the peripheral parts. A calibration equation was developed to corr ect for the inhomogeneity.