2470 High Voltage SourceMeter Instrument Reference Manual
Section 4: Sourcing and measuring
2470-901-01 Rev. A /
May
2019
4-13
Using SCPI commands:
To change to 4-wire sensing for current measurements, send the command:
:SENSe:CURRent:RSENse ON
To change to 4-wire sensing for voltage, replace
CURRent
with
VOLTage
. For resistance, replace
CURRent
with
RESistance
.
Using TSP commands:
To change to 4-wire sensing, send these commands:
smu.measure.func = smu.FUNC_DC_VOLTAGE
smu.measure.sense = smu.SENSE_4WIRE
To assign a different measure function, replace
smu.FUNC_DC_VOLTAGE
with one of the following:
•
For current measurements:
smu.FUNC_DC_CURRENT
•
For resistance measurements:
smu.FUNC_RESISTANCE
Ohms measurements
You can make ohms measurements using either 2-wire or 4-wire sensing.
Accuracy of 2-wire resistance measurements
The 2-wire sensing method has the advantage of requiring only two test leads. However, as shown in
the following figure, the total lead resistance is added to the measurement. This can seriously affect
the accuracy of 2-wire resistance measurements, particularly with low resistance values.
Figure 60: Two-wire resistance sensing for a high impedance DUT
