Keithley 2701, Руководство по обслуживанию

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1-24 Performance Verification Model 2701 Service Manual
Verifying AC current
Check AC current accuracy by applying accurate AC voltage current at specific frequencies
from the AC current calibrator to the Model 7700 input terminals and verifying that the dis-
played readings fall within specified limits. Follow these steps to verify AC current:
1. Connect the Model 7700 CH21 H and L terminals to the calibrator as shown in
Figure 1-11 .
Figure 1-11
Connections for Model 7700 AC current verification
2. Install the Model 7700 in Slot 1 of the Model 2701, 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. Select the AC current function by pressing the ACI key.
4. Set the Model 2701 for the 1A range. Close Channel 21 by pressing the CLOSE key
and keying in 121.
5. Source 1A and 3A, 1kHz full-scale AC currents as summarized in Table 1-12 and verify
that the readings are within stated limits.
6. Press the OPEN key to open Channel 21.
Table 1-12
Plug-in module ACI limits
ACV range Applied AC voltage Reading limits @ 1kHz (1 year, 18°C to 28°C)
1A
3A 1.000000A
3.00000A* 0.99860 to 1.00140A
2.9817 to 3.0183A
* 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.
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
CH21
Output
HI
Output
LO
Calibrator (Output AC Current)
Model 7700