ISO 19036 pdf download – Microbiology of the food chain 一Estimation of measurement uncertainty for quantitative determinations

ISO 19036 pdf download – Microbiology of the food chain 一Estimation of measurement uncertainty for quantitative determinations.
3,1.9
measurement uncertainty
MU
parameter, associated with the result of a measurement, that characterizes the dispersion of the values that could reasonably be attributed to the measurand (1L5)
Note Ito entry: The parameter may be. For example, a standard deviation (or a given multiple oUt), or the half- width olan Interval having a stated level of confidence.
Note 2 to entry: Measurement uncertainty comprises, in general, many components. Some of these components may be evaluated from the statistical distribution of the results of a series of measurements and can be characterized by experimental standard deviations. The other components, which also can he characterized by standard deviations, are evaluated from assumed probability distributions based on experience or other information.
Note 3 to entry: It is understood that the result of the measurement La the best estimate of the value of the measurand and that all components of uncertainty, Including those arising from systematic effects, such as components associated with corrections and reference standards, contribute to the dispersion.
ISOLIRCE: ISO/IEC Guide 98-3:2008. 2.2.3. modified — The preferred term has been changed from “uncertainty of measurement to measurement uncertainty”.]
3.1.10
standard uncertainty
uncertainty of the result of a measurement expressed as a standard deviation
ISOURCE: ISO/IEC Guide 98.3:2008. 211, modified — The symbol has been addedj
3.1.11
combined standard uncertainty
u(y)
srandord Uncertainty (3J.JQ) o(the result of a measurement when that result is obtained from the values of a number of other quantities, equal to the positive square root of a sum of terms, the terms being the variances or covariances of these other quantities weighted according to how the measurement result varies with changes in these quantities
ISOURCE: lSO/IEC Guide 98-3:2008,2.3.4. modified — The symbol has been added.]
3.1.12
expanded uncertainty
U
quantity defining an interval about the result of a measurement that may be expected to encompass a
large fraction of the distribution of values that could reasonably be attributed to the measurand(3J,,S)
Note ito entry: The fraction may be regarded as the coverage probability or level of confidence of the interval.
Note 210 entry: To associate a specific level of confidence with the interval defined by the expanded uncertainty requires explicit or implicit assumptions regarding the probability distribution characterized by the measurement result and its combined standard uncertainty (IL.U). the level of confidence that may be attributed to this interval can be known only to the extent to which such assumptions may be justified.
Note 3 to entry: An expanded uncertainty U is calculated from a combined standard uncertainty u(y) and a coverugefactork (1113) Lising
ISOIJRCE: ISO/IEC Guide 98-3:2008, 2.3.5, modified— The symbol has been added and Note 3 to entry has been replaced.