Fluke Digital Multimeter - Page 50

©Fluke Calibration 2011 Basics Of Measurement Uncertainty for DMM Calibration 50
Overall uncertainty
budget
Source of
Uncertainty
Type
Ui
Uncertainty
Value
(Amps)
Sensitivity
Coefficient
Probability
Distribution
Coverage
Factor
Standard
Uncertainty
(Amps)
Degrees
of
Freedom
Repeatability
A
u
1
11.410
-3
1
Normal
1
11.410
-3
4
Calibrator
B
u
2
810
-3
1
Normal
2.58
3.110
-3
Resolution
B
u
3
510
-3
1
Rectangular
2.910
-3
Current
Measurement
Combined
u
C
- -
Assumed
Normal
-
12.1610
-3
5.2
How do you calculate the overall
effective Degrees of Freedom?

3
