Water softening system having two flow paths and two different measures of water hardness

摘要

Disclosed is a water softening system (1) having an ion exchange device (6) comprised of an ion exchange resin (5) and a supply vessel (8) for supplying a regenerating solution (7) for regenerating the ion exchange resin (5). The system (1) also has an admixing device (9) for the mixing of raw water and softened water, a conductivity sensor (12) for measuring the conductivity of the raw water, at least one flow meter (12, 13) and an electronic control unit (11). The electronic control unit (11) has a memory having a multitude of calibration characteristics stored therein, by means of which first and second total water hardness values may be determined from the conductivity of the water using first and second calibration characteristics. The first calibration characteristic is different from the second calibration characteristic, and at least in a section of the first calibration characteristic, the total hardness derived from the first calibration characteristic is larger than the total hardness derived from the second calibration characteristic.