Abstract: The present disclosure relates to an apparatus for monitoring the soft water conducted in a main flow, which includes a hardness measuring cell, a first secondary flow line branching off from the main flow and leading to the hardness measuring cell, and a second secondary flow line leading away from the hardness measuring cell and feeding into the main flow, wherein the two secondary flow lines and the hardness measuring cell are connected to a multiway valve.

Abstract: The present disclosure relates to an apparatus for monitoring the soft water conducted in a main flow, which includes a hardness measuring cell, a first secondary flow line branching off from the main flow and leading to the hardness measuring cell, and a second secondary flow line leading away from the hardness measuring cell and feeding into the main flow, wherein the two secondary flow lines and the hardness measuring cell are connected to a multiway valve.

Abstract: The object of the invention is a process for treating, in particular softening water by ion exchange in a regenerable medium, with exhaustion of the medium being measure in a bypass provided parallel to the main flow of the medium to the water sampling point and a suitable system in which the bypass line includes a measuring cell. It is therefore the aim of the invention to secure a flow through the measuring cell irrespective of that of the medium. In order to achieve this aim, control of the main flow and a suitable increase of the pressure gradient in the bypass, irrespective of the flow, is effected by means of a control unit (40), increasing the pressure reduction in the measuring cell irrespective of the flow. The throttling of the main flow results in a relative reduction of the bypass resistance and therefore all increased flow to the measuring cell.