Method for checking the operation of sensors situated in a dialysis liquid circuit

A method for checking operation of at least one sensor situated in a dialysis liquid circuit of an artificial kidney, the artificial kidney including an exchanger with two compartments separated by a semi-permeable membrane, one compartment being connected to the dialysis liquid circuit while another compartment is intended to be connected to an extracorporeal blood circuit, the method comprising the steps of:

• circulating a noncorporeal reference liquid having a known characteristic value in the extracorporeal blood circuit;
• circulating a dialysis liquid in the dialysis liquid circuit and measuring a first value upstream and downstream from the exchanger;
• varying a composition of the dialysis liquid, and measuring a second value upstream and downstream from the exchanger for the varied composition;
• calculating a characteristic value of the reference liquid on the basis of said first and second values;
• comparing the calculated characteristic value with the known characteristic value of the reference liquid;
• and
• determining that said sensor is functioning properly when the calculated characteristic value is substantially equal to the known characteristic value.