When adding color to your process, today as in the past, processors focus on product quality and cost. Accuracy was, and still is, the key to achieving these objectives. Not just accuracy when first set up, but continuous accuracy over the entire production run.

Since our introduction of the first reasonably priced gravimetric blender in 1989, the product we gave the name “Weigh Scale Blender”, gravimetric has virtually replaced volumetric blending for one simple reason; gravimetric assures that we maintain these two objectives, hour after hour, day after day, without operator intervention or frequent monitoring and correction.

In the past, over coloring was the norm. Today, blending by weight has solved that problem.

Today no one questions that Gravimetric is better then Volumetric. Instead, ads now often make sales claims about their blenders high level of “accuracy”. This paper about accuracy, which Steve Maguire wrote over 25 years ago, still remains true today. There is still no standard way to measure “accuracy”.

Claims continue about accuracy based on “percentage” values, but seldom is there supporting data or explanation of what their number means. We are left to guess at the meaning.

Steve Maguire in 1990 with the launch of the WSB 140R 

This paper explains what they may, or may not, be saying. Then you can decide what accuracy means.

 Download Steve’s explanation here.