A radiotracer method is proposed by which it is possible to evaluate flow parameters (like sorption coefficient, dispersion coefficient, flow velocity or real cross section area of the flow stream) only with the use of integrals of the break-through curves. The integrals may be directly obtained as a result of measurements in the total-count system. The method is applied in the case of an irrevesible loss of tracer due to its sorption on the solid phase of the medium or/and to its radiation decay.