8508A
Users Manual
Table 6-10. Resistance Verification Points and Sequence (cont)
8508A Range Resistance Tolerance
1
HiVΩ
2
20 MΩ 0 GΩ Perform input zero operation to calibrator zero output
10 MΩ ± 0.000202 MΩ
200 MΩ 0 GΩ
Perform input zero operation to calibrator zero output
100 MΩ ± 0.00870 MΩ
2 GΩ 0 GΩ Perform input zero operation to calibrator zero output
1 GΩ ± 0.0003150 GΩ
20 GΩ 0 GΩ
Perform input zero operation to calibrator zero output
1 GΩ ± 0.012675 GΩ
1. Based on 365 day Tcal ±1°C 99 %CL Absolute specifications. See comments in Applicable Verification Tolerance section above
regarding the impact of calibration uncertainties and use of other specifications.
2. Ranges require separate input zero operation in each resistance mode.
DC Current Checks
Equipment Configuration
1. Ensure that the calibrator output is set to
STANDBY and configured for Internal
Guard (
EX GRD is deselected).
2. Connect the equipment as described for Routine Adjustment.
3. Press the
DCI key
4. Confirm that the 8508A is configured for internal guard (External Guard is
deselected) by checking that the
ExGd legend does not appear on the left-hand
display.
Procedure
Repeat the following sequence for each range, starting with the 200µA range and
working up to the 20A range, as listed in Table 6-11. An input zero operation is
performed on each 8508A range prior to performing the range verification measurements
with the calibrator set to zero by range locking the calibrator in the range from which the
output will be obtained.
1. On the 8508A, select the required range.
2. On the Calibrator, select the positive Range Gain Point Output value.
Deselect
AUTO to range lock the calibrator.
3. On the Calibrator, set zero output.
Select
OPR to operate the calibrator output.
4. On the 8508A, press the Input key, and select
Zero Rng to initiate the zeroing
operation.
The busy legend will appear, and then extinguish when the operation is complete.
5. On the Calibrator, select the positive Range Gain point Output value.
6. Note the 8508A reading. Compare the result with the allowable tolerance, taking into
account any known error from nominal of the calibrator for this output.
6-46
To Next Page
Loading...
