Keithley 2750 User Manual page 114

Model 2750 Multimeter/Switch System User's Manual
Measuring resistance of voltage-sensitive devices
Dry circuit ohms should be used for any device that could be damaged by high open-
circuit voltage. If not sure, and the slightly degraded accuracy is not a consideration, it is
good practice to use dry circuit ohms to measure low resistance.
Enabling/disabling dry circuit ohms
Dry circuit ohms is enabled by pressing SHIFT and then DRYCKT. When enabled, the
DCKT annunciator is on. When dry circuit ohms is enabled, offset-compensated ohms is
automatically enabled (OCOMP annunciator turns on). If you do not wish to use offset-
compensated ohms, press SHIFT and then OCOMP.
Dry circuit ohms is disabled by again pressing SHIFT and then DRYCKT.
Performing dry circuit ohms measurements
Dry circuit ohms can only be performed on the Ω4 function using the 1Ω , 10Ω , 100Ω, or
1kΩ range as follows:
NOTE
1.
2.
NOTE
3.
4.
5.
Make sure the INPUTS switch is in the correct position. To use front panel
inputs, it must be in the "F" (out) position. For switching modules, it must be in
the "R" (in) position.
Do not make connections to the DUT until after dry circuit ohms is enabled in
step 2.
If a switching channel is presently closed (displayed), press OPEN to open it.
Select the 4-wire ohms measurement function by pressing Ω4, and enable dry cir-
cuit ohms by pressing SHIFT and then DRYCKT (DCKT annunciator turns on).
When DRYCKT is enabled, offset-compensated ohms will also enable (OCOMP
annunciator turns on). If you do not wish to use offset-compensated ohms, press
SHIFT and then OCOMP.
Make 4-wire connections to the DUT as shown in
Use the RANGE up and down keys to select the 1Ω , 10Ω , 100Ω , or 1kΩ range, or
press AUTO to enable auto range.
Perform steps 4 through 8 of the
Basic DMM Operation
Figure
"Standard resistance measurements" procedure.
3-23
3-6B or Figure 3-7B.