Owon XDM Series - 4. Measurement Tutorial; Loading Errors (DC Voltage)

4.Measurement Tutorial
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4. Measurement Tutorial
Loading Errors (DC Voltage)
Measurement loading errors occur when the resistance of the DUT(Device-Under-Test) is
an appreciable percentage of the multimeter's input resistance, as shown below.
HI
LO
Ideal
Meter
R
s
V
s
R
i
V
s
= ideal DUT voltage
R
s
= DUT source resistance
R
i
= multimeter input resistance (10 MΩ or >10 GΩ)
Error
is
s
100 R
()
RR
%
×
=
+
To reduce the effects of loading errors and to minimize noise interference, set the
multimeter's input resistance to 10 GΩ for the 200 mVDC and 2 VDC ranges. The input
resistance is maintained at 10 MΩ for the 20 VDC, 200 VDC, and 1000 VDC ranges.