Estimation of measurement uncertainty in chemical analysis
3. The basic concepts and tools
Brief summary: This section presents the most basic concepts and tools for practical estimation of measurement uncertainty. First, the concepts of random quantities and distribution functions are introduced. Then the Normal distribution – the most important distribution function in measurement science – is explained and its two main parameters – the mean value and standard deviation – are introduced (3.1). Based on standard deviation the concept of standard uncertainty is introduced (3.1, 3.2). Thereafter the A type and B type uncertainty estimation is introduced (3.3). The mean value of random quantities is also a random quantity and its reliability can be described by the standard deviation of the mean (3.4). Besides the normal distribution three more distribution functions are introduced: rectangular and triangular distribution (3.5) as well as the Student distribution (3.6).
