ABSTRACT
International and national regulations are requiring that testing and calibration laboratories provide estimates of uncertainty with their measurements. Many balance users are having questions about determining weight measurement
uncertainty, especially if their quality control (QC) programs have provided estimates of measurement system “bias and precision.” Part of the problem is the terminology used to describe the quality of weight and mass measurements. Manufacturer’s specifications list several performance criteria but do not provide estimates of the “uncertainty” of measurements made using an electronic balance. Several methods for estimating the uncertainty of weight and mass measurements have been described in various publications and regulations in recent years. This chapter will discuss the terminology used to describe measurement quality, i.e., “accuracy,” “precision,” “linearity,” “hysteresis,” “measurement uncertainty” (MU), and the various contributors to MU, and will discuss the advantages and limitations of various methods for estimating MU. The methods include using
0 the manufacturer’s specifications at specified conditions,
balance calibration data, and
measurement control program data.
