K vp estimate intercomparison between Unfors XI, Radcal 4075 and a new CDTN multipurpose instrument

This work compares results obtained using 3 (three) different instruments capable of non-invasively estimating the voltage applied to the electrodes of an x-ray emission equipment, namely the Unfors model Xi R/F, the Radcal Corporation model 4075 R/F and a new CDTN multipurpose instrument. Tests were carried out using the Pantak Seifert Model 320 Hs x-ray machine with equal setups for all instruments undergoing comparison. Irradiations were performed for different conditions of voltage and filtration. Although all instruments show a similar tendency to increase the k Vp estimate when aluminum filters are placed in the path of the x-ray beam, they may all be satisfactorily adopted in quality control routines of x-ray equipment by means of estimation of the applied voltage. The importance of using equally calibrated measurement instruments and according to manufacturers instructions became clear; in case it is not possible to follow these requirements, measurement-correcting methods must be applied. Using the new multipurpose instrument, the k Vp estimate is satisfactory even if the x-ray beam intensity is filtered in approximately one-tenth value layer. (author)