Abstract: A method and a device for taking samples when measuring pH, conductivity, redox potential and/or other ion-concentrations in liquids, including washing of electrodes and a suction circuit. The sampling is characterized in that a vacuum is created in the sampling chamber (1) at (8) in order to suck the sample. After the sampling and measuring has been performed, the sampling chamber (1) is drained, and the sampling chamber (1) is then sprayed with a detergent solution and/or water by one or more jet nozzles (4). The nozzle orifices face upwards, ensuring that the jets hit the tip (9) of the measuring electrode (3) or measuring electrodes, and also the inlet (16). Generating a vacuum at (8) simultaneously with the jetting causes water and/or detergent solution to be sucked into the suction circuit, cleaning it of dirt and deposits.