Page 4 - Industrial Technology EXTRA - 29th June 2020

ADHESIVES...

Dispensing: what do we mean

by accuracy and repeatability?

Adhesives dispensing products can be variously described as accurate, precise

and/or repeatable, but what exactly do we mean by those terms? Here, Rachel
Chancellor, Marketing Manager at adhesives specialist Intertronics, explains what
dispensing accuracy and repeatability means for manufacturers

ccuracy, precision and repeatability are dispenses the required volume within a 1% overall
criteria that have a big impact on tolerance.
productivity through reduction of material Accuracy isn’t the whole equation, though.
Awaste, quality-based rejects, and rework. Accuracy only tells us how close we get to our
But what exactly do we mean when we say requirements on average. It doesn’t tell us how
“accurate”, “precise” and “repeatable”? often we are achieving the same result; that’s
Put simply, accuracy is getting a result within “precision” or “repeatability”.
acceptable tolerance of your requirements. Whether Precision, or repeatability, tells us how
that be dispensing a certain volume or putting the consistent our process is. That might be consistently
material in the right place on your component, dispensing the same dot size, or consistently putting
accuracy is a measurement of how closely that is it in the same place. Going back to our preeflow
achieved. One example of this is the preeflow eco- eco-PEN example, the eco-PEN is >99%
PEN, which is ±1% accurate, meaning that it repeatable, meaning that more than 99% of the

ACCURACY VERSUS PRECISION/REPEATABILITY

June 2020 • INDUSTRIAL TECHNOLOGY EXTRA! • p4