Test Equipment; Test Conditions - National Instruments SCXI-1121 Calibration Procedure

Test Equipment

Test Conditions

© National Instruments Corporation
NI recommends that you use the equipment in Table 1 to calibrate the
SCXI-1121. If these instruments are not available, use the requirements
listed in Table 1 to select a suitable substitute.
Equipment
Calibrator
DMM
Resistors
If you do not have custom connection hardware, you need the following
connectors:
• Terminal block, such as the SCXI-1320
• Shielded 68-pin connector cable
• 50-pin ribbon cable
• 50-pin breakout box
• SCXI-1349 adapter
These components give easy access to the individual pins on the
SCXI-1121 front and rear connectors.
Follow these guidelines to optimize the connections and environment
during calibration:
• Keep connections to the SCXI-1121 short. 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-1121.
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-1121 to
ensure that the measurement circuitry is at a stable operating
temperature.
Table 1. Test Equipment
Recommended
Model
Fluke 5700A
NI 4070
—
3
Requirements
50 ppm
5 1/2-digit, 15 ppm
120 Ω and 800 Ω, ±10%
SCXI-1121 Calibration Procedure