National Instruments NI PXI-5922, Руководство пользователя, Страница: 16 / 21

16 | ni.com | NI 5922 Calibration Procedure
8. Call
niScope_FetchMeasurement
(niScope Fetch Measurement VI) with the
following parameters:
•
channelList :
"0"
• timeout :
1.0
• scalarMeasFunction :
NISCOPE_VAL_VOLTAGE_AVERAGE
9. Generate the negative voltage listed in Table 6 with the calibrator.
10. Wait 2,500 ms for the output of the calibrator to settle.
11. Call
niScope_InitiateAcquisition
(niScope Initiate Acquisition VI) with the
following parameter:
•
vi : The instrument handle you obtained from
niScope_init
12. Call
niScope_FetchMeasurement
(niScope Fetch Measurement VI) with the
following parameters:
•
channelList :
"0"
• timeout :
1.0
• scalarMeasFunction :
NISCOPE_VAL_VOLTAGE_AVERAGE
13. Calculate the error in the vertical gain as a percentage of input using the following formula:
where a = the measured positive voltage
b = the measured negative voltage
c = the applied positive voltage
d = the applied negative voltage
Compare the resulting percent error to the Calibration Test Limits or the Published
Specifications listed in Table 6. If the result is within the selected test limit, the device has
passed this portion of the verification.
14. Repeat steps 1 through 13 for each iteration listed in Table 6, changing the Range , Positive
Input , and Negative Input values accordingly.
15. Move the calibrator to the oscilloscope input channel 1 and repeat steps 1 through 14,
changing the value of the channelList parameter from
"0"
to
"1"
.
Table 6.
NI 5922 Vertical Gain Stimuli
Iteration
Range
(V)
Positive
Input (V)
Negative
Input (V)
Calibration
Test Limits Published
Specifications
1 2 0.9 -0.9 ±0.0293% ±0.05%
2 10 4.5 -4.5 ±0.0293% ±0.05%
error
a b
–
c d
–
------------
 
 
1
–
100

=