Mittausepäilyä

Mittausepäilyä, or measurement uncertainty, refers to the doubt about the quality of a measurement. It is a non-negative parameter that characterizes the dispersion of the values that could reasonably be attributed to the measurand. Every measurement result is inherently uncertain. This uncertainty arises from various factors including the limitations of the measuring instrument, the environment in which the measurement is taken, and the skill of the operator.

Understanding and quantifying measurement uncertainty is crucial for ensuring the reliability and comparability of measurement results. It allows for informed decisions about whether a measurement result is fit for its intended purpose. For example, in scientific research, uncertainty helps determine if an experimental result is statistically significant. In manufacturing, it ensures that products meet specified tolerances.

The estimation of measurement uncertainty typically involves identifying all significant sources of error, quantifying their contribution to the overall uncertainty, and then combining these contributions using statistical methods. Common sources include systematic errors, such as calibration offsets, and random errors, like fluctuations in readings. Different methods exist for estimating uncertainty, with the Guide to the Expression of Uncertainty in Measurement (GUM) being a widely accepted international standard. Expressing uncertainty is often done by stating a numerical value, typically as a standard uncertainty or an expanded uncertainty, which provides a range within which the true value of the measurand is expected to lie with a certain level of confidence.