Water preparation apparatus with a chlorine sensing system

A water preparation apparatus comprising:

• a chlorine sensing system configured to receive water from a water source, the chlorine sensing system including a control unit and an electrical circuit electrically coupled to an electrode pair;
• a water pretreatment filter located downstream from the chlorine sensing system;
• a reverse osmosis filter fluidly coupled to the water pretreatment filter and configured to receive purified water from the water pretreatment filter;
• and
• an electrodeionization (“EDI”) module fluidly coupled to the reverse osmosis filter,
• wherein the chlorine sensing system is configured to determine an amount of total chlorine in the water by:
• applying at a first time, using the electrical circuit and the electrode pair, a source voltage to the water,
• stop applying at a second time, using the electrical circuit, the source voltage to the purified water,
• measuring after the second time, using the control unit, the electrical circuit, and the electrode pair, an electrical parameter of the water, and
• determining, via the control unit, the amount of total chlorine in the water based on the measured electrical parameter.

A water preparation apparatus comprising:

• a water pretreatment filter configured to receive water from a water source;
• a reverse osmosis filter fluidly coupled to the water pretreatment filter and configured to receive purified water from the water pretreatment filter;
• an electrodeionization (“EDI”) module fluidly coupled to the reverse osmosis filter;
• and
• a chlorine sensing system fluidly coupled to the EDI module, the chlorine sensing system including a control unit and an electrical circuit electrically coupled to an electrode pair,
• wherein the chlorine sensing system is configured to determine an amount of total chlorine in the purified water by:
• (i) measuring, via the control unit electrically coupled to the electrical circuit, a background voltage VB using the electrode pair, the background voltage VB associated with tri-iodide in the chlorine sensing system before introduction of the purified water,
• (ii) receiving the purified water,
• (iii) measuring a baseline voltage V0 using the control unit and the electrode pair, the baseline voltage V0 associated with tri-iodide present in the purified water,
• (iv) at a first time applying, using the electrical circuit, a source voltage to the purified water,
• (v) at a second time stop applying the source voltage,
• (vi) measuring a voltage V1 using the control unit and the electrode pair for a time t1, the voltage V1 associated with an amount of the tri-iodide in the purified water, and
• (vii) determining, via the control unit, the amount of total chlorine in the purified water using the baseline voltage V0, the background voltage VB, and the voltage V1.