Abstract: A method of determining an enhancement in rust-prevention of treated water by applying an electric current between a first cathode electrode and an anode electrode, and between a second cathode electrode and the anode electrode, wherein the first cathode electrode, the second cathode electrode, and the anode electrode are immersed in treated water; applying a comparative electric current between a first comparative cathode electrode and a comparative anode electrode, and between a second comparative cathode electrode and the comparative anode electrode, wherein the first comparative cathode electrode, the second comparative cathode electrode, and the at least one comparative anode electrode are immersed in untreated water; and determining an antirust effect of the treated water based on a first potential difference across the first cathode electrode and the second cathode electrode, and a second potential difference across the first comparative cathode electrode and the second comparative cathode electrode.

Abstract: A determination device for determining an improvement in water quality, capable of determining it in no time, is provided. The device has a first measuring device for measuring by AC terminal electric conductimetry a capacitance of a first capacitor formed between a pair of electrodes immersed in untreated water to be supplied to a water quality-improving apparatus; a second measuring device for measuring by AC terminal electric conductimetry a capacitance of a second capacitor formed between a pair of electrodes immersed in water discharged by the apparatus; and a processor for calculating a ratio (Y/X) of a capacitance Y to a capacitance X wherein the capacitance X is a capacitance of the first capacitor outputted by the first measuring device when an AC frequency is 100 Hz or less, and the capacitance Y is a capacitance of the second capacitor at the same frequency outputted by the second measuring device.

Abstract: A determination device for determining an improvement in water quality, capable of determining it in no time, is provided. The device has a first measuring device for measuring by AC terminal electric conductimetry a capacitance of a first capacitor formed between a pair of electrodes immersed in untreated water to be supplied to a water quality-improving apparatus; a second measuring device for measuring by AC terminal electric conductimetry a capacitance of a second capacitor formed between a pair of electrodes immersed in water discharged by the apparatus; and a processor for calculating a ratio (Y/X) of a capacitance Y to a capacitance X wherein the capacitance X is a capacitance of the first capacitor outputted by the first measuring device when an AC frequency is 100 Hz or less, and the capacitance Y is a capacitance of the second capacitor at the same frequency outputted by the second measuring device.