Apparatus for measuring water hardness using ion selective electrode

An apparatus for determining hardness in water, said apparatus comprising:

• a first sodium ISE sensor coupled with a first reference electrode, said first sodium ISE sensor configured to receive hard water;
• a second sodium ISE sensor coupled with a second reference electrode, said second sodium ISE sensor in electrical communication with said first sodium ISE sensor, and configured to receive soft water;
• said first and second reference electrodes having a salt bridge therebetween;
• and
• at least one drain to receive outflow from effluent fluid from said first and second sodium ISE sensors.

An apparatus for determining hardness in water, said apparatus comprising:

• a first sodium ISE sensor coupled with a first reference electrode, said first sodium ISE sensor configured to receive a standardized sodium solution;
• a second sodium ISE sensor coupled with a second reference electrode, said second sodium ISE sensor in electrical communication with said first sodium ISE sensor, and configured to receive hard water;
• said first and second reference electrodes having a salt bridge therebetween;
• a third sodium ISE sensor configured to receive soft water with exchanged sodium;
• and
• at least one drain to receive outflow from effluent fluid from said second and third sodium ISE sensors.

An apparatus for measuring the total hardness in water of a water softener, comprising:

• a housing;
• an ion exchange column or vessel in a monovalent cationic form, the ion exchange column or vessel having an inlet and an outlet separately disposed and extending through the housing;
• a monovalent cation selective electrode positioned within the housing at said inlet or said outlet, said monovalent cation selective electrode capable of measuring monovalent cation activity, quantity, or concentration in the water;
• and
• a valve for receiving the water from said inlet and/or said outlet;
• wherein hard water flows through the water softener via the inlet and outlet to be measured by the monovalent cation selective electrode, and said electrode provides an electrical signal commensurate with the amount cation concentration measured at said inlet and at said outlet to provide for a differential measurement of these values in order to ascertain the amount of cation being generated by said softener.