Determination of real particle sizes on the basis of their autoradiographic picture

Differences between the identifications of large grains (up to some 10 microns) and submicron particles, the disadvantages of the microscopic method are reviewed. Model 192Ir fine-grains were used for studying the reconstruction of the real particle sizes from the autoradiographic spot diameters. The particles of different size were exposed up to 240 hours with several films. The examinations carried out with an Opton TGZ-3 particle-size analyser on 2500 samples and the Bartha and Kozma type microdensitometer showed good results, although they needed a very complicated process. The development of the method is going on. (K.A.)