Analysis of the results obtained in the calibration of electronic analytical balances

Measurement is everywhere, playing a vital role in our lives. All physical and chemical measurements affect the quality of daily life. Incorrect or inaccurate measurements can lead to wrong decisions and can have serious consequences both in financially and human health. The determination of mass influences a vast range of activities and is the dominant factor in the conduct of trade. Many chemical reference methods rely on gravimetric determinations. Health and safety and business costs may be vitally dependent on the accurate determination of mass which it´s an important source of measurement uncertainty in any analysis. For this purpose are used the balances, which are measuring instruments used to determine the mass of a sample (weighed object), generally by measuring the force that is exerted by the sample on its support in the gravitational field of the Earth [1]. At this moment, mechanical balances were replaced by electronic balances, which offer a better resolution and faster work. The main focus of the paper is the processing of experimental data obtained in the calibration of electronic analytical balances. In this way, in the paper are presented the measurements which are performed in the calibration, the calculation of the measuring results and the determination of measurement uncertainty (including the way to obtain errors and assigned uncertainties for any other reading within the calibrated weighing range). The article may be considered a useful guideline for: - operators working in calibration laboratories accredited in various fields where the weighing operations are part of their testing activities; - laboratories, or manufacturers using calibrated non-automatic weighing instruments for measurements relevant for the quality of production subject to QM requirements (e.g. ISO 9000 series, ISO 10012, ISO/IEC 17025); - accredited laboratories for the calibration of weighing instruments, etc.