Verifying Ac Current - Keithley 2750 Service Manual

Model 2750 Multimeter/Switch System Service Manual

Verifying AC current

Check AC current accuracy by applying accurate AC voltage current at specific frequen-
cies from the AC current calibrator to the Model 2750 input, and verify that the displayed
readings fall within specified limits. Follow these steps to verify AC current:
1. Connect the Model 2750 AMPS and INPUT LO jacks to the calibrator as shown in
Figure
2. Select the AC current function by pressing the ACI key.
Figure 1-4
Connections for Model 2750 AC current verification
Model 2750
Front Panel
Input
SENSE
LO
INPUT
Ω 4 WIRE
HI
350V
1000V
!
PEAK PEAK
LO
500V
PEAK
INPUT
F R
FRONT/REAR
CAT I AMPS
3A, 250V
Amps
3. Set the Model 2750 for the 1A range.
4. Source 1A and 3A, 1kHz full-scale AC currents as summarized in
verify that the readings are within stated limits.
Table 1-5
ACI limits
ACV Range Applied AC Voltage
1A
3A
* If the Fluke 5725A amplifier is not available, apply 2.2A from the calibrator. Reading limits for 2.2A are
2.1949 to 2.2051A.
1-4. Be sure the INPUTS switch is in the FRONT position.
Output
HI
Output
LO
1.000000A
3.00000A*
Performance Verification
Calibrator (Output AC Current)
Reading Limits @ 1kHz (1 year, 18°C to 28°C)
0.99860 to 1.00140A
2.9817 to 3.0183A
1-13
Table 1-5, and