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NI PXIe-4480//4481 Calibration Procedure
3.
Create and configure an AI voltage task on the device as shown in Table 8.
4.
Start the task.
5.
Acquire readings with the PXIe-4480/4481.
6.
Calculate the RMS amplitude of the acquired fundamental harmonic. The measured
amplitude represents V
1kHz
of the measured analog input channels referenced in Table 9 at
the 10 V range setting.
As an example, you can use the Extract Single Tone Information VI to help calculate RMS.
Note that the output of this VI is peak amplitude, and you must divide the result by √2 to
convert to RMS.
7.
Stop and clear the task.
8.
Repeat steps 2 through 7 for each row in Table 9. When performing step 2, instead of
1 kHz, configure the calibrator output to the frequency listed in Table 9. The calibrator
output amplitude remains constant. Compare this amplitude to the appropriate limits in
Table 9.
Note
The value of V
1kHz
is the measured amplitude of the 1 kHz tone, not the
nominal amplitude listed in Table 7.
9.
Repeat steps 2 through 8 for each range setting of the device. When performing step 2,
configure the calibrator output to the amplitude and frequency indicated for the range to be
verified. When performing step 3, set the
range
parameter to 5, 1, and 0.5 as required.
Table 8.
Voltage Gain Flatness Verification Configuration
Configuration
Value
Physical channel
Dev_name
/ai0 or
Dev_name
/ai0:5
Range
10 (V)
Coupling
AC
Terminal configuration
Pseudodifferential
Acquisition mode
Finite number of samples
Sample rate
1,250,000
Samples per channel
625,000