Meßwert

Meßwert, historically written with the ß, designates the value obtained from a measurement of a quantity. It is the numerical value together with the unit that results from a measuring process. The Meßwert is not guaranteed to equal the true quantity; the true value is generally unknown and can only be estimated within a measurement uncertainty.

In modern German spelling the standard form is Messwert; Meßwert appears in older texts. The term is widely used in metrology, science, engineering, and industry to describe the outcome of measurement, including the reported uncertainty.

Measurement uncertainty arises from instrument limits, observer influence, and environmental conditions. A Meßwert is typically reported with an uncertainty or confidence interval. Errors are categorized as systematic or random; calibration and traceability to standards help control them.

Obtaining a Meßwert involves planning, selecting a suitable instrument, taking readings, applying corrections, and reporting the result with units and an uncertainty. Repeated measurements yield a mean value and an estimate of random uncertainty; calibration and reference standards connect the result to SI units.

For example, measuring a rod with a caliper might yield a Meßwert of 12.34 cm with an expanded uncertainty of ±0.05 cm (k = 2).