NI 9227 Calibration Procedure
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© National Instruments
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3
Test Equipment
Table 1 lists the equipment recommended for the performance verification and adjustment
procedures. If the recommended equipment is not available, select a substitute using the
requirements listed in Table 1.
Test Conditions
The following setup and environmental conditions are required to ensure the NI 9227
meets
published specifications.
•
Keep connections to the device as short as possible. Long cables and wires act as antennas,
picking up extra noise that can affect measurements.
•
Verify that all connections to the device are secure.
•
Use shielded copper wire for all cable connections to the device. Use twisted-pairs wire to
eliminate noise and thermal offsets.
•
Maintain an ambient temperature of 23 °C ± 5 °C. The device temperature will be greater
than the ambient temperature.
•
Keep relative humidity below 80%.
•
Allow a warm-up time of at least 10 minutes to ensure that the NI 9227 measurement
circuitry is at a stable operating temperature.
Table 1.
Recommended Equipment
Equipment
Recommended
Model
Where Used
Requirements
Calibrator
Fluke 5522A
Accuracy,
Adjustment
Use a high-precision current
source with an accuracy
±500 ppm of 500
μ
A.
Function
Generator
NI 5421
Gain Matching,
Phase Matching
Use a function generator with an
output impedance of 50
Ω
capable of sourcing both 1 kHz
and 20 kHz ±10 VPK AC
sinusoidal signals with
amplitude uncertainty of ±10%
to a 50
Ω
load.
Termination
Resistor
—
Gain Matching,
Phase Matching
50
Ω
, 1 W, ±5%
Chassis
NI cDAQ-9178
All
—
