Oct
22
When developing a PLS models for quality parameter prediction, the deviation of measurement values from their mean must be shifted in time to account for the time required for a change in the input to impact the quality parameter. Similarly, these delays should be taken into account in the processing of the deviation values used …
Oct
15
The process operating points of a continuous process can shift with changes in the product grade that is manufactured. One example of this is a continuous reactor in which the target for output composition changes with product grades. To change the output composition, it is often necessary to change the operating point of one or …
Oct
08
The prediction of quality parameters using Partial Least Squares (PLS) models is often the preferred technique when dealing with collinear data where multiple process input changes impact similar process output measurements. Predictions based on this linear technique can be used to extrapolate outside the data range used in model development. Process interactions may be accounted …
Oct
01
One of the key objectives of a process control system is to maintain product quality parameters within specification. On-line analyzers that automatically provide measurements of material properties to the control system may be too expensive, may have proven to be unreliable, or simply may not be available because of the complexity of the sampling system …
