A dialysis system includes at least one pump to conduct a fluid through a fluid circuit, a conductivity meter to measure conductivity values of the fluid, at least one conductivity detector to measure conductivity values of the fluid, and a controller. The controller is configured to receive the conductivity values from the conductivity meter and the sensor values from the at least one conductivity detector, compute a plurality of representative conductivity values from the received conductivity values and a plurality of representative sensor values from the received sensor values, determine a first conductivity point associated with a first representative conductivity value and a first representative sensor value, determine a second conductivity point associated with a second representative conductivity value and a second representative sensor value； and compute a calibration curve based on the first and second calibration points.
