National Instruments NI 9234, Процедура калибровки, Страница: 11 / 17

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NI 9234 Calibration Procedure
4. Acquire a reference amplitude.
a. Create and configure an AI voltage task on the NI 9234 according to Table 12.
b. Configure the AI voltage task timing according to Table 13.
c. Enable the function generator.
d. Start the task.
e. Record the measured amplitude as Amplitude
Acq
.
f. Disable the function generator.
g. Clear the task.
5. Perform the following calculation using the recorded Amplitude
Acq
.
h. Compare the calculation result to the minimum CMRR limit of 40 dB.
6. Repeat steps 1 through h for each channel.
If the Common-Mode Rejection Ratio verification procedure determines that the NI 9234 is
outside of the limits, refer to
Worldwide Support and Services
for assistance in returning the
device to NI.
Table 12. NI 9234 Configuration for CMRR Verification
Min (V) Max (V) Scaled Units Channel Configuration
-5 5 Volts DC Coupled
Table 13.
NI 9234 Timing Configuration
Sample Mode Samples Per Channel Rate (kHz)
Finite Samples 16384 51.2
CMRR
20
10
log ×
–
Amplitude
Acq
0.5
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