Keysight 34450A Guia Del Usuario página 106

3 Measurement Tutorial
Thermal EMF caused by dissimilar metals can create a parasitic voltage in the
measurement circuit (VEMF). The thermal EMF can be caused by the input lead
connections or internally in resistor R. In general, this voltage will not change with
the current applied to the resistor.
Ideal
Meter
The voltage measured, and so the resistance calculated, is in error by V
offset compensation can reduce the errors caused by V
compensated measurement, the meter makes two voltage measurements, one
with the current source on and one with the current source off, and subtracts the
two measurements. The actual voltage drop across the resistor, and the
calculated resistance are obtained by:
First Reading -Second Reading = (I*R+V
Offset compensation can be used in 2-Wire or 4-Wire ohms measurements (only
available on 100 , 1 k and 10 k).
106
V EMF
E=IR+ V EMF
I=0
R
Ideal
Meter
I=0
) -V = I*R
EMF EMF
Keysight 34450A User's Guide
V EMF
V EMF =
E=(0*R)+
R
F. Using
EM
. To make an offset
EMF
V EMF