Abstract: A procedure and means for non-destructively measuring the distribution of the filler and/or coating materials in the thickness direction of paper or cardboard. Radiation from a radio-isotope source is used to excite in the material component its characteristic X-ray radiation, the intensity of this radiation being observed. Measurements are made on both sides of the paper and the contents of other filler components are also determined by X-ray absorption in order to eliminate the effects of these components disturbing the distribution measurement. The base weight of the paper is measured e.g. by beta radiation absorption. Measurements are made both by measuring the characteristic radiation of the material components excited in the paper with different radiator sources and with the aid of absorption measurements of radiation directly from the source or produced with its aid in transformation targets, thus eliminating the effects of these components.

Abstract: A procedure and means for non-destructive measuring of the distribution in the thickness direction of the filler and/or coating materials in paper or cardboard. Radiation emitted by an x-ray tube is used to excite in the material component to be examined, its characteristic x-ray radiation, the intensity of this radiation being observed. Measurements are made on both sides of the specimen. The contents of other filler components are also determined by x-ray absorption measurements, and the base weight of the paper, e.g. by beta radiation absorption. Measurements of the characteristic radiation, elicited with constant energy x-ray radiation as well as absorption measurements of radiation obtained directly from the x-ray tube and of radiation produced in transformation targets are made in order to eliminate by calculation the disturbing interaction of the filler components.