Measurements of Uranium Concentrations in the Front Glass of CRT

Abstract

Concentrations of uranium contained in the front glass of CRT (cathode ray tube) for television sets are measured by two methods: fission track counting and radioactivation analysis. The measurements are also made for other kinds of glass such as a laboratory dish. Systematic errors in the present experiment are shown to be less than about 15% for the uranium concentrations more than 3 ppm from the comparison between the results obtained with these two methods. Moreover, it is presented that the uranium concentrations obtained are 0.4-12ppm for the glass of CRT, whereas they are 0.2-0.7ppm for other kinds of glass. The presence of nuclides of uranium series should be, therefore, taken into account for measuring exactly the radiations near the front glass of CRT.