Keithley 6430, Instruction Manual

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Ohms Measurements 4-9
Ohms source readback
With ohms source readback enabled, the instrument measures the actual source value used
for ohms measurements and then uses that measured value for reading calculations. Normally,
ohms source readback should be left enabled for optimum measurement accuracy. However,
disabling source readback will allow you to make valid ohms measurements with the source in
compliance. Use the following procedure to enable or disable ohms source readback:
1. Press CONFIG then
Ω
.
2. Select SRC RDBK, then press ENTER.
3. Select DISABLE or ENABLE as desired, then press ENTER.
4. Press EXIT to return to normal display.
NOTE Readings in the compliance field will be invalid with source readback disabled.
6-wire ohms measurements
The 6-wire ohms measurement configuration allows you to make accurate resistance mea-
surements on resistor networks and hybrid devices in cases where internal resistance connec-
tion nodes are not accessible. The combination of 4-wire Kelvin connections and guarded ohms
features eliminates the effects of internal parallel resistances that could degrade measurement
accuracy and reduce measurement speed. The basic procedure for setting up the SourceMeter
for 6-wire ohms measurements is covered below.
NOTE
See Figure 2-7 for 6-wire ohms connections. See also Section 2, “Ohms guard” and
Section 5, “Guard” for more information. Keep in mind that ohms guard is only
available at the rear panel of the mainframe.
1. Press CONFIG then
Ω
to display the CONFIG OHMS menu.
2. Select GUARD, then press ENTER.
3. Select OHMS, then press ENTER.
4. Press EXIT to return to normal display.
5. Press MEAS then
Ω
to select the ohms measurement function.
6. Select the appropriate measurement range, or use autoranging if desired.
7. Turn on the output by pressing the ON/OFF OUTPUT key.
8. Take readings from the display.
9. Turn the output off when done by pressing the ON/OFF OUTPUT key.