PXIe-4468 Calibration Procedure
© National Instruments Corporation
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Terms and Definitions
DUT
DUT is an acronym for Device Under Test and refers to the NI product
being calibrated. For this procedure, DUT refers to the PXIe-4468.
As-Found Limits
These limits are derived from the published specifications for the DUT.
NI uses these limits to determine if the DUT is performing within the
recommended calibration interval specifications at the time of
calibration and before any adjustment is performed.
As-Left Limits
These limits are derived from the published specifications for the DUT
minus guardband to ensure a high probability that the DUT will meet its
specifications over the next recommended calibration interval.
Functional Test
Functional Tests determine whether the DUT is operating correctly.
Functional tests are not directly related to performance specifications.
Verification
Verification evaluates the measured calibration results against the
defined As-Found Limits. The result of the evaluation is expressed as a
Pass/Fail condition in the calibration certificate using an established
evaluation formula.
Adjustment
Adjustment performs a set of operations on the DUT to optimize the
measurement performance and conform it to the assigned calibrated
values.
Reverification
Reverification evaluates the measured calibration results against the
As-Left limits after adjustment. The As-Left limits may be tighter than
the As-Found limits.
Recommended
Calibration Interval
This interval indicates the recommended period between each round of
verification and adjustment of the DUT. There is a high probability that,
within this interval, the DUT will remain within the published warranted
performance specifications. Some measurement DUTs have warranted
specifications for different calibration intervals, for example: 24 hours,
90 days, 1 year, and 2 years. In this case, the specification depends on
the calibration cycle chosen by the user.
