Keithley 2750, Service Manual

Page: 41 / 179

Model 2750 Multimeter/Switch System Service Manual Performance Verification 1-29
770
0 V
eri
fication
2. Install the Model 7700 in Slot 1 of the Model 2750, then turn on the power, and
allow the unit to warm up for two hours before proceeding. Be sure the front panel
INPUTS switch is set to the REAR position.
3. Set the calibrator for 4-wire resistance with external sense on.
4. Select the Model 2750 4-wire resistance function by pressing the

4 key. Close
Channel 1 by pressing the CLOSE key, then ENTER for “SINGLE” channel, and
keying in 101.
5. Set the Model 2750 for the dry circuit resistance function by pressing SHIFT then
DRYCKT.
Figure 1-15
Connections for Model 7700 dry circuit resistance verification
H L H L
AMPS
H L H L H L H L H L H L
LO
CH21 CH22 CH11 CH12 CH13 CH14 CH15 CH16
H L H L H L H L
CH17 CH18 CH19 CH20
SENSE
(OHMS, 4 WIRE)
INPUT
(V, 2 WIRE)
H L H L H L H L
CH7 CH8 CH9 CH10
H L H L H L H L
H L H L H L H L
INPUT SENSE CH1 CH2
CH3 CH4
CH5 CH6
CH1
CH11
Output
HI
Output
LO
Resistance Calibrator
Note: Use shielded, low-thermal cables
to minimize noise.
Model 7700
Sense HI
Sense LO