Fluke Digital Multimeter - Page 64

©Fluke Calibration 2011 Basics Of Measurement Uncertainty for DMM Calibration 64
MET/CAL manages &
analyses the uncertainties
Number of Measurements = 5
Value 1 = 10.07
Value 2 = 10.01
Value 3 = 10.02
Value 4 = 10.04
Value 5 = 10.06
UUT Indicated = 10.04
Standard Deviation = 0.02549509757
Standard uncertainty = 0.01140175425
Sensitivity Coefficient = 1
Degrees of Freedom = 4
System Actual = 10
System Accuracy = 0.008
Confidence interval of spec = 2.58
1 Sigma Spec = 0.003126379456
Sensitivity Coefficient = 1
Degrees of Freedom = 1e+200
UUT Resolution = 0.01
Resol. Standard Uncertainty. = 0.002886751346
Sensitivity Coefficient = 1
Degrees of Freedom = 1e+200
Combined Std. Uncertainty = 0.01216490061
Effective Deg. of Freedom = 5.186506
Standard Uncertainty = 0.01207040471
Coverage Factor = 2.567104753
Expanded Uncertainty = 0.031263794
Calculated
Total
Uncertainty
Repeatability
Uncertainty
Calibrator
Uncertainty
Resolution
Uncertainty
Measurement
Details
With MET/CAL the user configures:
• Specific statistics used
• Confidence / Coverage
• Number of measurements
• Accuracy of the standard
In the cal or test procedure you also
specify test parameters:
• Test point
• UUT resolution
In the test process, MET/CAL provides
the uncertainty details (our example is
shown to the right)
Details are permanently stored in the
data base. They accessible for reports
& future analysis.
MET/CAL Data for
our example