Precision volumetric measuring and mixing apparatus

An apparatus for measuring and mixing a first liquid with a second liquid and a third liquid, comprising:

• a tank having a mixing chamber therein;
• a first and a second supply line for connecting the mixing chamber to a first source of liquid;
• a gross control valve disposed in the first supply line connected to the first source and a fine control valve disposed in the second supply line connected to the first source;
• a supply line for connecting the mixing chamber to a second source of liquid;
• a gross control valve disposed in the supply line connected to the second source;
• a supply line for connecting the mixing chamber to a third source of liquid;
• a fine control valve disposed in the supply line connected to the third source;
• a liquid level detector for measuring the total volume of liquid present in the mixing chamber;
• and
• a controller, operable in response to signals output from the detector representative of the total volume within the mixing chamber as continuously measured by the detector, for actuating in accordance with a predetermined sequence the gross and the fine control valves in their respective supply lines from the first source, the second source and the third source.

An apparatus for measuring and mixing a first liquid with a second liquid, a third liquid, and a fourth liquid, comprising:

• a tank having a mixing chamber therein, the tank being a right circular cylinder, the mixing chamber having a predetermined working volume therein;
• a first supply line for connecting the mixing chamber to a first, second, third and fourth source of liquid;
• a control valve disposed in the supply line connected to each source;
• a liquid level detector for measuring the total volume of liquid present in the mixing chamber, the liquid level detector being operative to sense a predetermined minimum change in liquid volume;
• and,
• a controller, operable in response to signals output from the detector representative of the total volume within the mixing chamber as continuously measured by the detector, for actuating in accordance with a predetermined sequence the control valves in their respective supply lines from the first source, the second source, the third source and the fourth source,
• wherein the length-to-diameter ratio of the mixing chamber is such that the predetermined minimum change detectable by the detector is less than one percent (1%) of the predetermined working volume of the mixing chamber.