Apparatus and method for metals free reduction and control of resistivity of deionized water

A method for reducing the resistivity of a first fluid comprising the steps of:

• delivering the first fluid through a first inlet to a vessel, the first inlet being formed at a first end of the vessel;
• selectively delivering a second fluid through a second inlet to the vessel for mixing with the first fluid to cause a reduction in the resistivity of the first fluid by forming resistivity-reduced first fluid, wherein the second inlet is formed at the first end of the vessel;
• measuring the resistivity of the resistivity-reduced first fluid in the vessel by directly withdrawing the resistivity-reduced first fluid through a dedicated first port that is integrally formed in the vessel at the first end of the vessel and protrudes outwardly from the vessel and directly opens into a hollow interior of the vessel and controlling the delivery of the second fluid to the vessel based on measured resistivity values;
• and
• discharging the resistivity-reduced first fluid from the vessel through an outlet associated therewith when the resistivity value of the resistivity-reduced first fluid is at a predetermined target value or within a predetermined target range, wherein the outlet is integral to and extends outwardly from the vessel at the first end thereof with the dedicated first port and the outlet being formed in a first corner of the first end of the vessel and the first inlet and the second inlet are formed in a second corner of the first end of the vessel;
• wherein the first inlet, second inlet, vessel and outlet are constructed such that fluid paths in which the first and second fluids flow are defined by metal free materials, whereby the resistivity of the first fluid is reduced without addition of metal ions to the first fluid.

An apparatus for reducing the resistivity of a first fluid comprising:

• a vessel having a first inlet for receiving the first fluid, an outlet, and a dedicated first port that is separate and spaced from the outlet, wherein the outlet and first port are integral to and protrude outwardly from the vessel at two different locations along the vessel, wherein the first port includes a first port conduit that terminates in a drain connector that is configured to mate with a drain conduit;
• a valve disposed along the first port for controlling flow within the first port conduit;
• a source of a second fluid that is selectively delivered to the vessel through a second inlet for mixing with the first fluid for reducing the resistivity of the first fluid by forming resistivity-reduced first fluid;
• a resistivity sensor that is in fluid communication with the first port conduit of the dedicated first port and measures the resistivity of the resistivity-reduced first fluid, the resistivity sensor being disposed along the dedicated first port proximal to the drain connector, the resistivity sensor being disposed between the valve and the drain connector;
• wherein a distance between the first port and the outlet is less than a distance between the first port and the first inlet, the first port and the outlet being disposed in one corner of the vessel;
• wherein the apparatus is constructed such that both the first and second fluids flow along fluid paths defined by metal free materials, whereby the resistivity of the first fluid is reduced without addition of metal ions to the first fluid and the outlet and first port are formed such that the resistivity-reduced first fluid can flow directly from a hollow interior of the vessel into either the outlet or the first port.