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NI PXIe-4339 Calibration Procedure
Test Conditions
The following setup and environmental conditions are required to ensure the NI PXIe-4339
meets published specifications.
•
Keep connections to the NI PXIe-4339 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 TB-4339/B/C are secure.
•
Use shielded copper wire for all cable connections to the TB-4339/B/C. Use twisted-pair
wire to eliminate noise and thermal offsets.
•
Maintain an ambient temperature of 23 °C ± 5 °C. The NI PXIe-4339 temperature will be
greater than the ambient temperature.
•
Keep relative humidity below 80%.
•
Allow a warm-up time of at least 15 minutes to ensure that the NI PXIe-4339 measurement
circuitry is at a stable operating temperature.
•
Ensure that the PXI/PXI Express chassis fan speed is set to HIGH, that the fan filters are
clean, and that the empty slots contain filler panels. For more information, refer to the
Maintain Forced-Air Cooling Note to Users
document available at
ni.com/manuals
.
Initial Setup
Refer to the
NI PXIe-4339 and TB-4339/B/C Installation Guide and Terminal Block
Specifications
for information about how to install the software and hardware and how to
configure the device in Measurement & Automation Explorer (MAX).
Note
When a device is configured in MAX, it is assigned a device identifier. Each
function call uses this identifier to determine which DAQ device to verify or to verify
and adjust. This document uses
Dev1
to refer to the device name. In the following
procedures, use the device name as it appears in MAX.
Verification
The following performance verification procedures describe the sequence of operation and
provide test points required to verify the NI PXIe-4339. The verification procedures assume that
adequate traceable uncertainties are available for the calibration references.
The NI PXIe-4339 has eight independent analog input channels. Each channel can be configured
for voltage mode or ratio mode. Voltage
mode is used to measure voltages, and ratio mode is
used to provide excitation and measure from bridge-based sensors.
You can verify voltage mode for any or all of the channels depending upon your desired test
coverage. Ratio mode verification requires the use of voltage mode channels to internally
measure the excitation voltage of the ratio mode channel that is being verified. Voltage mode
channels used in ratio mode verification require that you determine gain adjust and offset adjust
values (ratio verification adjustment factors) prior to verifying ratio mode accuracy.
