Patent ID: 8191397
Filing Date: 2012-06-05
Classification: G01N

Abstract:
1. A process for calibrating one or more concentration sensors of a liquid distribution system having a first chemical distribution line, including a first chemical supply source that houses a first chemical and a first flow control device, a second chemical distribution line, including a second chemical supply source that houses a second chemical that differs from the first chemical and a second flow control device, the second chemical distribution line coming together with the first chemical distribution line to form a first blended chemical distribution line, and a first concentration sensor disposed along the first blended chemical distribution line, the process comprising the steps of: a) flowing a baseline fluid through the first concentration sensor via the first chemical distribution line, the second chemical distribution line or an alternative line specifically for the baseline fluid in order to establish a baseline calibration reading in the first concentration sensor; b) calibrating the first flow control device located on the first chemical distribution line and the second flow control device located on the second chemical distribution line in order to achieve an exact flow rate for each of the flow control devices; c) setting a target flow rate for each of the first flow control device and the second flow control device; d) allowing the first chemical from the first chemical supply source and the second chemical from the second chemical supply source to flow along their associated chemical distribution lines and come together to form a first chemical blend that flows along the first chemical blend distribution line; e) passing the first chemical blend through the first chemical blend distribution line and through the first concentration sensor in order to obtain a concentration sensor value for the first chemical blend; f) comparing either manually or using a programmable logic controller the concentration sensor value obtained in step e) to the known concentration sensor value of the chemical blend as established by a model; and g) based on the comparison of step f), adjusting the value of the concentration sensor if necessary.