A Film Method for Estimating Peak Kilovoltage, Total Filtration and Roentgen Output of Self-rectified Dental X-ray Machines

Abstract

A film method for determining peak kilovoltage, total filtration and roentgen output of self rectified dental X-ray machines is presented. This system is based upon the differential absorption of the X-ray beam by copper and aluminum absorbers as measured by reading optical densities at four points on exposed film. Ratios of relative exposures based upon these densities have been used to produce equations for calculating kVp, total filtration, and an exposure factor which corrects for energy dependence of the film. Results are presented of the statistical evaluation of machine-to-machine variation in the estimation of the above mentioned parameters. This method is used by the Public Health Service's Division of Radiological Health for analyzing the Surpak, a package for surveying X-ray machines by mail.