Method of constant metrological label and summary correction factor for measurement of radioactive concentration of pure β-emitters

New approach has been given to the technik of metrological labels which has been based on application of single label for measuring activity of different pure β-sources. The method has been discussed of determination of correction factor for coincidence methods, including corrections which have connection with sensitivity of a β-detector relative to γ-quantums, internal capture and complicity of decay scheme. The principle of summary correction factor has been used in the technik of metrological methods of measurement for determination of dependence of the summary correction factor from correlation of activity of label and β-source in a summary radiation source. Installation has been described for conducting measurements by the given method. In the installation are used: in the β-channel, - liquid scintillator and in the γ-channel, - Na(Tl) crystal. Results have been given of measurement of following β-sources: Ni-63, C-14, S-35, Ca-45, Tl-204, Sr-90 + Y-90, P-32. Methodology has been proposed of determination of systematic errors, connected with the method of metrological labels which have been discussed