Abstract: A chemical mixing system for mixing ingredients at desired concentrations concentration within a qualification range. Batches of the mixed chemical are mixed in a relatively small mix vessel and transferred to a relatively large mix drum. The concentration of the chemical within the mix drum is measured by a concentration monitor. If the measured concentration of the chemical in the mix drum is within the qualification range, the batches of chemical in the mix vessel are mixed to the desired concentration. If the measured concentration of the chemical in the mix drum is below the qualification range, the batches of chemical in the mix vessel are mixed to a high concentration which is greater than the desired concentration. If the measured concentration of the chemical in the mix drum is above the qualification range, the batches of chemical in the mix vessel are mixed to a low concentration which is less than the desired concentration.

Abstract: A chemical mixing system for mixing ultra pure water and concentrated HF to a desired concentration within a qualification range. Batches of the mixed chemical are mixed in a relatively small mix vessel and transferred to a relatively large mix drum. The concentration of the chemical within the mix drum is measured by a concentration monitor. If the measured concentration of the chemical in the mix drum is within the qualification range, the batches of chemical in the mix vessel are mixed to the desired concentration. If the measured concentration of the chemical in the mix drum is below the qualification range, the batches of chemical in the mix vessel are mixed to a high concentration which is greater than the desired concentration. If the measured concentration of the chemical in the mix drum is above the qualification range, the batches of chemical in the mix vessel are mixed to a low concentration which is less than the desired concentration.

Abstract: Apparatus and method for accurate measuring and mixing of chemicals is disclosed. The apparatus includes one or more metered vessels having a container of predetermined volume and at least one constricted vent tube therein. By mounting a sensor on the constricted vent tube, a greatly amplified measurement of the precise chemical volume in the metered vessel is provided. The apparatus and method of the present invention readily lends itself to a variety of applications and can be adapted to handle virtually any form of chemical mixing, diluting, or generating process.