Workshop: T05

T05 (PM Only)

Weighing Practices: A Risk-Based Approach to Selection, Calibration and Testing of Weighing Instruments

Author/Presenter: Dr. Ian Ciesniewski

Courtesy of: Mettler-Toledo Inc.


Abstract(s): Did you know that a balance calibration is incomplete, without a correctly calculated, corresponding statement of measurement uncertainty? Or that balance measurement uncertainty is almost wholly independent of loaded mass? Did you know that a high majority of analytical balance weighing inaccuracies occur outside of the balance, but can be attributed to a variety of influences within the control of the user or his/her organization?

It is a fact that most calibration regimes are either almost completely, or contain strong elements of, legacy calibration techniques that have been passed directly down from mechanical weighing instruments, even though the components of measurement uncertainty exhibit themselves differently, for an electronic weighing instrument.

Many organizations “Over test” without actually generating much meaningful metrology.

During this session, we will break down how measurement uncertainty exhibits itself, across the capacity of an electronic balance or scale. We will cover how to correctly assess and assign a Measurement Uncertainty budget for an electronic balance or scale, and discuss modern, robust, risk-based approaches to the assesment and estimation of significant, contributing uncertainty components, in order to build a thorough, yet scientifically-sound risk-based metrology program for bench or floor weighing instruments.

We will also discuss phenomena that affect the accuracy of weighing, to illustrate how easy it is to create poor weight data!  To contrast this, you will learn how to overcome these potential sources of error, and optimize a balance metrology regime. This course focuses on:


– Factors influencing Measurement Uncertainty

– Balance location and set up

– User testing

– Personal weighing technique

– Increasing productivity from your weighing equipment