RM-26999 Calibration Procedure
© National Instruments Corporation
7
Initial Equipment Setup
1.
Verify that the calibrator has been calibrated within 1 year and that DC Zero
Calibration has been performed within the last 30 days.
Note
Consult the calibrator user documentation for calibration instructions.
2.
Verify that the DMM has been calibrated within 1 year. Verify that ACAL (self-
calibration) has been performed within the last 24 hours or when the
temperature drifts more than
±
1
°
C from last ACAL temperature. The DMM
must also be within
±
5
°
C from T
CAL
. T
CAL
is the temperature at which an
external calibration was performed on the DMM.
Note
Conducting ACAL on the DMM provides additional correction for errors that
result from measurement, such as temperature drift. Refer to the DMM user
documentation for more information on conducting ACAL. Account for
additional uncertainty if ACAL is not performed correctly or if T
CAL
is outside
the bounds of
±
5
°
C.
3.
Verify that the calibrator and DMM have warmed up for at least 1 hour before
making any measurements for this procedure.
4.
Allow the calibrator and DMM to settle before taking any measurements.
Note
NI recommends a settling time of 10 seconds. Refer to the calibrator and
DMM documentation for more information about manufacturer-
recommended settling times.
5.
Clean any oxidation from the banana connectors on the cables before
connecting them to the calibrator, DMM or DUT.
Note
Oxidation tarnishes the copper plugs so that they appear dull rather than
shiny and increases thermal EMF.
