Methodological basis of a rho processor for the direct determination of densities in boreholes

It is shown that in boreholes the simultaneous use of two-detector gamma-gamma apparatus and a ''rho'' processor makes possible the measurement and the analogue registration of density log. In the absence of mud cake the base equation of the KRGG-2-120-60sY detector is derived by simple mathematical methods from the equation of the primary Compton-scattering. An approximate method is given to include the corrections caused by mud cake of less than 1-1.5 cm thickness. (author)