Contribution
Distribution
Uncertainty
Standard Deviation
Notes
Electrostatic
voltmeter accuracy
Rectangular
±1%
= 1/%
From manufacturer's datasheet or calibration report
Accuracy of simulator voltage setting
Rectangular
10 V or ±0.25% at 2 kV
= 0.25/%
May be significant at lowvoltages
Measurement repeatability
Standard deviation
11.6 V or 0.58%
0.58%
Calculated from a series of 10 tests
Current source accuracy
Rectangular
±0.1%
=0.1/%
From external multimetermanufacturer's data sheet
Oscilloscope vertical accuracy
Rectangular
±1%
= 1/%
From manufacturer's data sheet or calibration report; measurement made near full scale
Dc amplitude repeatability
Standarddeviation
0.21%
0.21%
Calculated from a series of 10 tests
Measurement systemrise time
Rectangular
+0, –1.0%
=0.5/%
From Table VII, 1% is chosenmto bracket the 0.75% loss
Peak current
Standarddeviation
2.16%
2.16%
Calculated from a series of 100 tests
Combined uncertainty, uc(y)
Normal
2.41%
2.41%
Combining the standard deviation values above
Expanded uncertainty
Normal
4.82% =2.00x2.41
N/A
Since uc(y)/s(q)=1.11, must calculate veff ; veff = 94 so k=2 from Table I
Table VIII. Example of peak-current uncertainty calculation.

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