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National Instruments Corporation
3
SCXI-1125 Calibration Procedure
Calibration Interval
Calibrate the SCXI-1125 at a regular interval as defined by the
measurement accuracy requirements of your application. NI recommends
that you perform a complete calibration at least once every year. You can
shorten this interval based on the accuracy requirements of your
application.
Password
The default password for password-protected operations is
NI
.
Test Equipment
NI recommends that you use the equipment in Table 1 to calibrate the
SCXI-1125. If these instruments are not available, use the requirements
listed in Table 1 to select a suitable substitute.
Test Conditions
Follow these guidelines to optimize the connections and the environment
during calibration:
•
Keep connections to the SCXI-1125 as short as possible. Long cables
and wires can act as antennas, picking up extra noise and thermal
offsets that affect measurements.
•
Use shielded copper wire for all cable connections to the SCXI-1125.
Use twisted-pair wire to eliminate noise and thermal offsets.
•
Maintain the ambient temperature between 18 °C and 28 °C.
•
Keep relative humidity below 80%.
•
Allow a warm-up time of at least 15 minutes for the SCXI-1125 and
30 minutes for the DAQ device to ensure that the measurement
circuitry is at a stable operating temperature.
Table 1.
Test Equipment
Equipment
Recommended Model
Requirements
Calibrator
Fluke 5700A
50 ppm
DAQ Device
NI 6281
16-bit minimum
DMM
NI 4070 or Agilent 34401A
6 1/2 digit, 15 ppm
Terminal Block
SCXI-1320
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