The conductivity of dialysis fluid

Dialysis fluid consists of a solution of inorganic salts that are dissociated in electrically charged ions. These ions can move in an electric field giving the salt solution electrically conducting properties, called conductivity. The conductivity of the dialysis fluid is a parameter well suited for measuring the total concentration of salt. The conductivity is easy to measure with reasonable accuracy and the measuring device is usually very stable over time. It can be used for both proportioning and monitoring of the concentrate intermixing. The conductivity behaviour of a salt solution is however complicated and depends in a non-linear way on temperature, total salt concentration and salt/glucose composition. The accuracy of the conductivity measurement is given by the calibration. A successful calibration requires good knowledge about the measuring device and the calibration solutions.