Fluke 8062A - Page 39

Operation Instructions
Operation
2
2-17
E B
E S
I M
Ammeter Shunt
RI
dy12f.eps
Es = Source Voltage
RI = Load resistance + Source resistance
Im = Measured current (display reading in amps)
Eb = Burden voltage (calculated)
Eb = meas. current [(200/current range in mA) + .35]
Error:
Error in % = 100 x Eb/(Es - Eb)
Error in A = (Eb x Im)/(Es - Eb)
Example:
ES = 15V
RI = 100 kΩ
Im = 148.51 µA (.14851 mA)
Eb = 148.51 x 10
-6
x [(200/.2) + .35]
= 148.51 x 10
-6
x 1000.35 = 148.56 mV
Max, error in % = 100 x [148.56 mV/(15V - .14856V)] = 1.0003%
Add this to the range spec. accuracy
Max. error in % = 1.0003% ±(.2% + 2 digits)
Max. error in A = (148.56 mV x 148.51 µA)/(15000 mV - 148.56 mV)
= 1.486 µA
Add 1.486 µA to the reading for correct current
Figure 2-11. Calculating Burden Voltage Error