National Instruments PXIe-4480, Calibration Procedure, Page: 13 / 34

NI PXIe-4480/4481 Calibration Procedure | © National Instruments | 13
Voltage Offset Accuracy Verification
Complete the following steps to verify the voltage offset accuracy:
1.
Using the equipment described in Table 1 (PXIe-4480) or Table 2 (PXIe-4481), connect the
module as shown in Figure 1.
2. Create and configure an AI voltage task on the device as shown in Table 3.
3. Start the task.
4. Acquire readings with the PXIe-4480/4481.
5. On a per channel basis, average all of the acquired samples.
6. Stop and clear the task.
7. Compare the averaged values to the appropriate limits in Table 4. The average is the offset
of the 10 V range.
8. Repeat steps 2 through 7 for each range of the device. When performing step 2, set the
range parameter to 5, 1, and 0.5 as required.
Table 3. Voltage Offset Accuracy Verification Configuration
Configuration Value
Physical channels
Dev_name
/ai0:5
Range 10 (V)
Coupling DC
Terminal configuration Pseudodifferential
Acquisition mode Finite number of samples
Sample rate 102,400
Samples per channel 102,400
Table 4. Voltage Offset Accuracy Limits
Range (V)
As Found Test Limit As Left Test Limit
Lower Limit
(mV)
Upper Limit
(mV)
Lower Limit
(mV)
Upper Limit
(mV)
10 -5.0 5.0 -0.2 0.2
5 -2.2 2.2 -0.1 0.1
1 -0.8 0.8 -0.05 0.05
0.5 -0.65 0.65 -0.05 0.05