EURAMET cg-18 – state-of-the-art calibration guideline for non-automatic weighing instruments

Abstract

This paper presents a state-of-the-art strategy for calibrating non-automatic weighing instruments (NAWIs), based on the international calibration guideline EURAMET cg-18. While existing national and legacy guidelines have only dealt with measurement uncertainty at the time of calibration, EURAMET cg-18 also provides advice for the so-called uncertainty of a weighing result, which describes the device performance during day-to-day usage. Furthermore, as a consequence of the uncertainty of a weighing result, the concept of minimum weight is introduced. The minimum weight is the smallest amount of mass that must be weighed on the device while still adhering to a predefined relative weighing tolerance requirement. The concept of minimum weight is the most important practical and quality relevant implication of NAWI calibration, as it is the prerequisite to achieve the necessary accuracy commensurate with the quality requirements of the weighing process.