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NI VirtualBench Calibration Procedure
3.
—Perform an external adjustment of the instrument that adjusts the
calibration constants with respect to standards of known values.
4.
—Repeat the verification procedure to ensure that the instrument is
operating within its specifications after adjustment.
These steps are described in more detail in the following sections.
FGEN Test Equipment
Table 16 lists the equipment recommended for the FGEN performance verification and
adjustment procedures. If the recommended equipment is not available, select a substitute using
the requirements listed in the table.
FGEN Test Conditions
Follow these guidelines to optimize the equipment and the environment during calibration:
•
Keep connections to the device as short as possible. Long cables and wires act as antennae,
picking up noise that can affect measurements.
•
Use a USB connection between the PC and VirtualBench.
•
Verify that all connections to the device, including front panel connections, are secure.
•
Keep relative humidity between 10% and 80% noncondensing.
•
Allow a warmup time of at least 30 minutes to ensure that the VirtualBench is at a stable
operating temperature.
•
Plug the VirtualBench, PC, and the test equipment into the same power strip to avoid
ground loops.
•
Verification limits are defined assuming the same test equipment is used during verification
and adjustment.
•
Maintain an ambient temperature of 23 ±5 °C. The device temperature will be greater than
the ambient temperature.
Table 16.
Recommended Equipment
Equipment
Recommended
Model
Minimum Requirements
Digital multimeter
(DMM)
NI PXI-4071
DC V accuracy: 21 ppm
DC input impedance: ≥1 GΩ
DC A accuracy: 310 ppm
Banana
plug-to-BNC cable
Pomona 4530-C
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