Fluke 5500A, Service Manual

Page: 74 / 296

5500A
Service Manual
3-20
3-24. Calibration Constants Report, Spreadsheet Format
ACTIVE=,0,STORED=,0,OLD=,0
VDAC_Z1, 4.003, 4.003, 4.003, 4.003
VDAC_Z2, 6.703, 6.703, 6.703, 4.003
VDAC_RATIO, 6.303, 6.303, 6.303, 6.703
VDAC_G, 5.802, 5.802, 5.802, 5.802
VDAC_N, 5.802, 5.802, 5.802, 5.802
IDAC_Z1, 4.003, 4.003, 4.003, 4.003
IDAC_Z2, 6.403, 6.403, 6.403, 4.003
IDAC_RATIO, 5.903, 5.903, 5.903, 6.703
IDAC_G, 5.802, 5.802, 5.802, 5.802
IDAC_N, 5.802, 5.802, 5.802, 5.802
(continued)
3-25. Performance Verification Tests
The following tests are used to verify the performance of the 5500A Calibrator. If an
out-of-tolerance condition is found, the instrument can be re-calibrated using the front
panel or the remote interface as described previously in this chapter.
Use the same test equipment and connection methods as used in the preceding
calibration procedures.
Zero the 5500A Calibrator before testing by completing “Zeroing the Calibrator” as
described next.
The performance tests have reserved columns for recording the Measured Value and
Deviation (%).
3-26. Zeroing the Calibrator
Zeroing recalibrates internal circuitry, most notably dc offsets in all ranges of operation.
To meet the specifications in Chapter 1, zeroing is required every 7 days, or when the
5500A Calibrator ambient temperature changes by more than 5
°
C. Zeroing is
particularly important when your calibration workload has 1 m
Ω
and 1 mV resolution,
and when there are significant temperature changes in the 5500A Calibrator work
environment. There are two zeroing functions: total instrument zero (ZERO) and ohms-
only zero (OHMS ZERO).
Complete the following procedure to zero the calibrator. (Note: The 5500A Calibrator
rear panel CALIBRATION switch does not have to be enabled for this procedure.)
1. Turn on the Calibrator and allow a warmup period of at least 30 minutes.
2. Press the
R
key.
3. Install a copper short circuit in the front panel TC connector (total instrument zero
only).
4. Press the
S
key, opening the setup menu.
5. Press the CAL softkey, opening the calibration information menu.
6. Press the CAL softkey.
7. Press the ZERO softkey to totally zero the 5500A Calibrator; press the OHMS
ZERO softkey to zero only the ohms function. After the zeroing routine is complete
(several minutes), press the
R
key to reset the calibrator.