NI USB-443x Calibration Procedure
8
ni.com
3.
Using Figure 2 as a guide, create and configure an AI voltage task on the NI USB-443
x
as shown
in Table 5.
4.
Acquire readings with the NI USB-443
x
.
5.
Calculate the amplitude of the acquired 1 kHz fundamental tone in V
rms
, and compare the
amplitude to the limits in Table 6.
6.
Repeat steps 1 through 5 for each analog input channel that you want to verify. Connect the output
of the calibrator to the channel being verified in step 1. In step 3, replace
aix
in the physical
channel parameter with the channel being verified.
NI recommends that you verify each channel, but you can save time by verifying only the channels
used in your application.
AI DC Coupled
Gain Accuracy Verification
Complete the following steps to verify DC coupled gain accuracy:
1.
Connect the output of the calibrator to the channel you want to verify on the device.
2.
Output 0 VDC from the calibrator.
Table 5.
AI AC Coupled Gain Accuracy Verification Configuration for NI USB-443
x
Configuration
Value
Minimum value
–10.0
Maximum value
10.0
Terminal configuration
Pseudodifferential
Acquisition mode
Finite number of samples
Rate
102400.0
Samples per channel
65,536
Coupling
AC
Physical channel
Dev_name/ai
x
*
*
Dev_name is the name shown for the NI USB-443
x
in MAX.
x
refers to the channel number.
Table 6.
AI AC Coupled Gain Accuracy Limits for NI USB-443
x
Calibrator Output Amplitude (V
rms
)
Device Input Amplitude
(One Year Limits)
Min (V
rms
)
Max (V
rms
)
6.36
6.350
6.370
