Page 11 of 12
HTSPRT Model 96178 Iss.06 – 03/11
GLOSSARY OF METROLOGICAL TERMS
ACCURACY OF MEASUREMENT
The closeness of the agreement between the result of a measurement and the (conventional) true value of the
measurand*
REPRODUCIBILITY OF MEASUREMENTS
The closeness of the agreement between the results of measurements of the same measurand, where the individual
measurements are carried out changing conditions such as:
method of measurement
oberserver
measuring instrument
location
conditions of use
time
NOTES:
1.
A valid statement of reproducibility requires specification of the conditions changed.
2.
Reproducibility may be expressed quantitatively in terms of the dispersion of the results.
UNCERTAINTY OF MEASUREMENT
An estimate characterising the range of values within which the true value of a measurand lies.
Note: Uncertainty of measurement comprises, in general, many components. Some of these components may be estimated
on the basis of the statistical distribution of the results of series of measurements and can be characterised by experimental
standard deviations. Estimates of other components can only be based on experience or other information.
STABILITY
The ability of a measuring instrument to maintain constant its metrological characteristics.
DRIFT
The slow variation with time of metrological characteristic of a measuring instrument.
*Measurand = a quantity subjected to measurement
