Mittausvakavuus

Mittausvakavuus is the Finnish term for measurement uncertainty. It refers to the doubt that exists about the result of a measurement and allows the quantification of the reliability of that result. In practice, measurement uncertainty is expressed as an interval around the measured value, within which the true value is expected to lie with a certain probability, typically 95 %.

In the uncertainty budget the standard uncertainty of every significant parameter is estimated. These standard uncertainties are combined to form the combined standard uncertainty using the square‐root‐of‐the‐sum‐of‐squares method for independent contributions. If parameters are correlated, covariance terms are added. The combined standard uncertainty is then expanded by a coverage factor, usually k = 2, to obtain the expanded uncertainty. This final value is quoted as ±U with the same units as the measured quantity.

Sources of measurement uncertainty include the instrument calibration, the precision of the calibration standard, environmental conditions, observer interpretation, and the mathematical model used to interpret the measurement signal. In many fields, the Guide to the Expression of Uncertainty in Measurement (GUM) provides a framework for constructing the uncertainty budget, while the International Vocabulary of Metrology (VIM) defines key terms.

Typical applications of measurement uncertainty are found in manufacturing quality control, scientific research, and any process where measurement decisions impact safety or performance. By reporting uncertainty, engineers and scientists can make better decisions, compare data sets consistently, and maintain traceability to international standards.