The measurement uncertainty in the calibration of a thermometer depends on the calibration method used, the uncertainty contri



Yüklə 187,5 Kb.
səhifə11/12
tarix26.12.2016
ölçüsü187,5 Kb.
#3354
1   ...   4   5   6   7   8   9   10   11   12
ubath s: Temporal stability: important characteristic of a bath is also short-term stability of a medium temperature. It strongly depends on type of regulation and flow of medium inside the bath. Since the calibration measurements are taken within short time interval, the short-time stability is relevant. For the time stability of a bath, temperature deviations of a reference thermometer are observed.

Example:


    1. Combined standard uncertainty

The combined standard uncertainty of a measurement result is taken to represent the estimated standard deviation of the result. It is obtained by combining the individual standard uncertainties ui, whether arising from Type A or Type B evaluation.

The quantity ui (i = 1, 2, …, N) is the contribution to the standard uncertainty associated with the output estimate y resulting from the standard uncertainty associated with the input estimate as described in sections 2.1 to 2.4.

The calculation of the degrees of freedom drives the uncertainty analysis in terms of confidence. The greater the degrees of freedom the higher is confidence in the parameter. The degrees of freedom are used to calculate the coverage factor.

Calibration laboratories should state an expanded uncertainty of measurement U, calculated by multiplying the standard uncertainty uc(y) by a coverage factor k.




Quantity

Brief description

Correction

Standard uncertainty

Distribution

Sensitivity coefficient

Uncertainty contribution

Tr, uTra

Standard deviation

0 K

2 mK

normal

1

2 mK


Yüklə 187,5 Kb.

Dostları ilə paylaş:
1   ...   4   5   6   7   8   9   10   11   12




Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur ©azkurs.org 2024
rəhbərliyinə müraciət

gir | qeydiyyatdan keç
    Ana səhifə


yükləyin