NI PXIe-4480/4481 Calibration Procedure
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© National Instruments
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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 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 10,000; 2,000; and 1,000 as
required.
9.
Repeat steps 1 through 8 for all input channels of the device. In step 1, connect the output
of the calibrator to the channel being verified. In step 3, replace
ai0
in the
physical
channel
parameter with the channel being verified.
IEPE Current Accuracy Verification (PXIe-4480 only)
Note
This performance characteristic is not affected by adjustment. Consequently,
reverification after adjustment is not necessary.
Note
During the IEPE verification, the Active LED on the device front panel will
illuminate RED, indicating a fault condition. This is an expected condition, and the
validity of the verification is unaffected. This is a result of the DMM’s low resistance
tripping the IEPE’s short detection monitor.
Complete the following steps to verify the IEPE current accuracy:
1.
Set the digital multimeter to DC Current mode and a range suitable to measure currents
between 4 mA and 20 mA.
2.
Using the equipment described in Table 1, connect the Current input of the digital
multimeter to the analog input channel 0 of the device.
3.
Create and configure an AI voltage task on the device as shown in Table 12.
4.
Start the task.
Table 12.
IEPE Current Accuracy Verification Configuration
Configuration
Value
Physical channel
Dev_name
/ai0
Range
10 (V)
Coupling
AC
Terminal configuration
Pseudodifferential
Excitation (IEPE)
0.004 (A)
Acquisition mode
Finite number of samples
Sample rate
102,400
Samples per channel
10,240