[Sensitometric characteristics of medical roentgenographic and fluorographic films. Sensitivity of the amplifying screens combined with a film].

Factors affecting the degree of sensitivity of roentgenographic and radiofluorographic films and of their combinations with fluorescent screens are considered. A method of films exposure with a roentgenosensitometer permitting it to determine the sensitivity in conditions closely approaching the ones used in practice and corresponding to the minimum of the isoopaque is suggested. A way for determining the sensitivity of films in m2-mJ1 and lx-1-c-1 is indicated. Numerical values for the sensitivity of the films and their combinations with the screens are given. It is shown that with Eef = 38 keV, T = 20 degrees C, exposure time of 0.4--1 sec and optical density 1.00 over general focusing the lower limit of the X-ray RM-1film sensitivity to the light of CaWO4-screens is 38 m2-mJ-1 and of the fluorographic film Pphi-3 to the light of the Zn0-68Cd0-32S--Ag-screens -- 14.6 m2-mJ-1 or 30 lx-1-c-1.