Device for measuring at least one measurand, comprising: a sensor device which comprises at least one sensor and, via at least one medium-carrying detection path, can be connected to one of a plurality of dialysis machines which each output a dialysis liquid flow as a medium flow, the at least one sensor being arranged to selectively detect at least one measurand with respect to the medium flow output by said one dialysis machine ; and a fluidic unit which is arranged upstream of the sensor device , can be connected to the plurality of dialysis machines via a plurality of paths carrying medium flows and is connected to the sensor device so as to pass on exactly one medium flow to the sensor device , wherein the fluidic unit is arranged to provide a flow control for dialysis liquid flows, namely by selectively choosing one of the plurality of medium flows output by the plurality of dialysis machines via the plurality of paths carrying medium flows and by supplying the one selected medium flow to the at least one sensor of the sensor device , and the fluidic unit is arranged to supply the sensor device with medium flows from the plurality of dialysis machine in a timely controlled manner and in a predetermined switching scheme, and/or to supply the sensor device with a currently selected medium flow from a currently selected dialysis machine for a predetermined period of time, characterized in that the predetermined period of time can be adapted or is adapted to detection times of a sensor system in the currently selected dialysis machine , and a plurality of predetermined periods of time are provided to be adaptable or to be adapted to detection times of a sensor system of each of the plurality of connected or connectable dialysis machines and are made available alternately in the manner of a time multiplex. a sensor device which comprises at least one sensor and, via at least one medium-carrying detection path, can be connected to one of a plurality of dialysis machines which each output a dialysis liquid flow as a medium flow, the at least one sensor being arranged to selectively detect at least one measurand with respect to the medium flow output by said one dialysis machine ; and a fluidic unit which is arranged upstream of the sensor device , can be connected to the plurality of dialysis machines via a plurality of paths carrying medium flows and is connected to the sensor device so as to pass on exactly one medium flow to the sensor device , wherein the fluidic unit is arranged to provide a flow control for dialysis liquid flows, namely by selectively choosing one of the plurality of medium flows output by the plurality of dialysis machines via the plurality of paths carrying medium flows and by supplying the one selected medium flow to the at least one sensor of the sensor device , and the fluidic unit is arranged to supply the sensor device with medium flows from the plurality of dialysis machine in a timely controlled manner and in a predetermined switching scheme, and/or to supply the sensor device with a currently selected medium flow from a currently selected dialysis machine for a predetermined period of time, characterized in that the predetermined period of time can be adapted or is adapted to detection times of a sensor system in the currently selected dialysis machine , and a plurality of predetermined periods of time are provided to be adaptable or to be adapted to detection times of a sensor system of each of the plurality of connected or connectable dialysis machines and are made available alternately in the manner of a time multiplex. <EOS>