The approach to creating standard means for reproducing units of volumetric activity of radon and thoron and flux density of radon from the soil surface is described based on the physical principles of reproducing these units of quantities and using as technical means for reproducing bubblers with a radioactive solution of radium salt, reference capacities of known volume, emanation chambers for generation of a toron, a gamma spectrometer with a semiconductor detector from highly pure germanium and radon radiometers. Reproduction consists in the physical realization of units in accordance with their definition as applied to the formation of radon and thoron in the radioactive rows of radium and thorium. The proposed approach will allow to determine the structural, structural and other technical solutions of standard measuring instruments, as well as specific techniques and methods of working with them. The creation of standard tools and technologies for reproducing units of volumetric activity of radon and thoron and the density of radon flux from the soil surface will ensure the unity and reliability of measurements in the field of ionizing radiation, traceability of units and bringing the characteristics of national standards in line with world achievements.
