Keithley 2750, Service Manual

Page: 34 / 179

1-22 Performance Verification Model 2750 Multimeter/Switch System Service Manual
Verifying AC voltage
Check AC voltage accuracy by applying accurate AC voltages at specific frequencies
from the AC voltage calibrator to the Model 7700 inputs and verifying that the displayed
readings fall within specified ranges.
CAUTION Do not exceed 300V RMS between the 7700 plug-in module INPUT H and
L terminals or between adjacent channels, or 8

10
7
VHz input, because
instrument damage may occur.
Follow these steps to verify AC voltage accuracy:
1. Connect the Model 7700 CH1 H and L INPUT terminals to the AC voltage calibra-
tor as shown in
Figure 1-10 .
Figure 1-10
Connections for Model 7700 AC volts verification
Table 1-10
Plug-in module DCV reading limits
Range Applied DC Voltage* Reading Limits (1 year, 18° to 28°C)
100mV
1V
10V
100V
1000V
100.0000mV
1.000000V
10.00000V
100.0000V
300.000V
99.9935 to 100.0065mV
0.999963 to 1.000037V
9.99965 to 10.00035V
99.9946 to 100.0054V
299.976 to 300.024V
*Source positive and negative values for each range.
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
Output
HI
Output
LO
Calibrator (Output AC Voltage)
Model 7700
Amplifier (Connect to calibrator)
Shielded
Cable