Fluke 9100 User Handbook Manual page 127

7.19.10 Calculating Power Uncertainty
The Power Uncertainty is based on the root sum square (rss) of the following three uncertainties (expressed in %):
1. Voltage (Main) Channel Amplitude Uncertainty
2. Current (Auxiliary) Channel Amplitude Uncertainty
3. Amplitude Uncertainty due to Phase Error
Power Uncertainty =
The following examples demonstrate how to calculate the power uncertainty at a specific calibration point.
(Note: All specifications used are 1 year specifications).
Example 1:
Calibrator Output 100V, 3A (at 60Hz) Power Factor 1.0 (Ø = 0 ).
1. Voltage Amplitude Uncertainty (From Section 7.4.1)
100V Specification :
2. Current Amplitude Uncertainty (From Section 7.19.7)
3A Specification :
3. Amplitude Uncertainty due to Phase Error (From Section 7.19.9)
Specifications:
Combined Phase Uncertainty
Ø
ERROR
2 2
U + U
Voltage Current
= 0.04%Rdg + 6.3mV(Floor)
= 0.04% + (6.3mV/100V) x 100
= 0.04% + 0.0063%
= 0.0463%
= 0.08%Rdg + 480 A(Floor)
= 0.08% + (480 A/3A) x 100
= 0.08% + 0.016%
= 0.096%
Voltage Channel Phase Uncertainty
Current Channel Phase Uncertainty
= 0.07 + 0.08
= 0.15
Section 7: Model 9100: Specifications
2
+ U
Phase
0.07
0.08
Final Width = 215mm
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