A measuring device for determining flow capacities d(V(z)) of electroconductive liquids having a conductivity LF through a container in the event of vertically (z direction) variable levels. The inventive measuring device is a conductivity measuring device comprising, inter alia, at least two electrodes extending in the z direction. The container and/or the conductivity measuring device is/are embodied in such a way that they can be described by at least one parameter function ƒPI(V(z)) dependent on V(z). At least one of said parameter functions must have an exponential dependence on V(z). A measuring element and a method for determining the total flow capacity d(V).