Fluke Digital Multimeter - Page 52

©Fluke Calibration 2011 Basics Of Measurement Uncertainty for DMM Calibration 52
Welch-Satterthwaite formula
in our example case
2.5
)10(2.91)10(3.11
4
)10(11.41
)10(12.16
434434434
43












v
eff
3
3
4
3
4
3
2
2
4
2
4
2
1
1
4
1
4
1
4
)()()(
)(
v
xuc
v
xuc
v
xuc
yu
c
eff
v


Our effective degrees of freedom considering all our uncertainties