(259c) Measuring Blend Time In Laboratory Agitated Vessels: A Case for the Acid-Base-Indicator Method

This paper will examine the sources of variance that can occur in the measurement of blend time.  Source of variance in blend time measurements can result from human error, statistical variance, or instrument accuracy.  These various sources of variance will be discussed as they relate specifically to the acid-base-indicator method.  Discussions will include the ability of the human eye to see color change and at what pixel level.  The video record/analysis technique will also be examined in terms of color and pixels.

The “partial blend time” technique will be described and how final blend time is determined.  Paper references will be provided to substantiate this "partial blend time" procedure.

A visual perspective of the acid-base technique along with techniques to minimize human error will be provided.  Assumptions and calculations used to determine the approximate degree of uniformity will also be submitted.  Details and logic for utilizing the partial blend time technique will be presented.

Pros and cons of this technique will be discoursed.