Keithley SourceMeter 2600 Series Reference Manual page 155

Series 2600 System SourceMeters Reference Manual
4.
5.
6.
Ohms sensing
Ohms measurements can be made using either 2-wire or 4-wire sensing (see
Section 3 for information on connections and sensing methods).
The 2-wire sensing method has the advantage of requiring only two test leads.
However, as shown in
accuracy of 2-wire resistance measurements, particularly with lower resistance
values. The 4-wire sensing method shown in
the effects of lead resistance by measuring the voltage across the resistor under
test with a second set of test leads. Because of the high input impedance of the
SourceMeter voltmeter, the current through the sense leads is negligible, and the
measured voltage is essentially the same as the voltage across the resistor under
test.
Figure 4-3
2-wire resistance sensing
Press the MEAS or MODE key to display voltage, then make sure that
AUTO measurement range is on.
Press the MEAS or MODE key to display ohms.
Turn on the output, then note the reading on the display. If necessary, press
the TRIG key to display continuous readings. Turn off the output when fin-
ished.
Figure
Return to
4-3, test lead resistance can seriously affect the
Figure 4-4
Section 4 topics
Basic Operation 4-19
minimizes or eliminates
2600S-901-01 Rev. A / May 2006