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NI 449
x
Calibration Procedure
If the recommended equipment is not available, select a substitute calibration standard that
meets the given specifications.
Test Conditions
The following setup and environmental conditions are required to ensure the NI 449x meets
published specifications:
•
Keep connections to the NI 449x as short as possible. Long cables and wires act as
antennae, picking up extra noise that can affect measurements.
•
Use the InfiniBand to BNC cable to connect signals to the NI 449x.
•
Keep relative humidity between 10% and 80%, noncondensing, or consult the device
documentation for the optimum relative humidity.
•
Maintain the ambient temperature between 18 °C and 28 °C, or refer to the device
specifications for the optimum temperature range.
•
Allow a warm-up time of at least 15 minutes to ensure that the measurement circuitry is at
a stable operating temperature.
•
Allow a warm-up time for all of the instruments and equipment according to the
manufacturer instructions.
BNC Cable
NI 4495/4496/4497/
4498/4499: quantity 17
NI PXIe-4492:
quantity 9
Pomona
Electronics 5697
All
Characteristic Impedance:
50
Ω
BNC T-Connector
NI 4495/4496/4497/
4498/4499: quantity 15
NI PXIe-4492:
quantity 7
Pomona
Electronics 4896
Adjustment
Characteristic Impedance:
50
Ω
BNC to Banana
Adapter
quantity 1
Pomona
Electronics 1269
AI gain
N/A
*
Accuracy is the sum of all errors, including initial accuracy and stability errors.
†
Timebase frequency verification is optional.
‡
The NI 449x is not isolated from EARTH ground. Isolation is required in the voltage source to avoid
the creation of a ground loop that could potentially degrade the DC measurement accuracy. Voltage
accuracy of the source is not a requirement because of the use of the digital multimeter in parallel.
Table 1.
Recommended Equipment (Continued)
Equipment
Recommended
Model
Parameter
Measured
Minimum Requirements
