![background image](http://html2.mh-extra.com/html/national-instruments/virtualbench/virtualbench_calibration-procedure_3421539033.webp)
NI VirtualBench Calibration Procedure
|
© National Instruments
|
33
•
Probe Attenuation
=
1x
•
Vertical Range
=
20
•
Vertical Offset
=
0
Note
Configure the oscilloscope calibrator for high impedance loads.
5.
Set the oscilloscope calibrator DC voltage output to -90% of the range, or -18 V.
6.
Wait at least 5 seconds for the oscilloscope calibrator to settle.
7.
Call
MSO Run
.
8.
Call
MSO Read
. Calculate and record the average analog waveform. Save this value as
V
meas_neg
.
9.
Set the oscilloscope calibrator DC voltage output to +90% of the range, or +18 V.
10. Wait at least 5 seconds for the oscilloscope calibrator to settle.
11. Call
MSO Run
.
12. Call
MSO Read
. Calculate and record the average analog waveform. Save this value as
V
meas_pos
.
13. Call
MSO Stop
.
14. Calculate the gain error as follows:
Where V
pos
and V
neg
are listed in Table 14.
Verify that this calculation falls within the limits in Table 14.
Table 14.
Oscilloscope Gain Verification Limits
Range (V)
V
pos
(V)
V
neg
(V)
1 Year Limits (%)
24 Hour Limits (%)
Lower
Upper
Lower
Upper
20
18
-18
-2
2
-0.8
0.8
10
9
-9
-2
2
-0.8
0.8
5
4.5
-4.5
-2
2
-0.8
0.8
2
1.8
-1.8
-2
2
-0.8
0.8
1
0.9
-0.9
-2
2
-0.8
0.8
0.5
0.45
-0.45
-2
2
-0.9
0.9
0.2
0.18
-0.18
-2
2
-0.9
0.9
0.1
0.09
-0.09
-2
2
-1
1
V
meas_pos
V
meas_neg
–
(
)
V
pos
V
neg
–
(
)
---------------------------------------------------------
1
–
100%
×