National Instruments SCXI-1141, Процедура калибровки

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© National Instruments Corporation 13 SCXI-1141/1142/1143 Calibration Procedure
Adjusting Filter AC Gain
The AC gain of the filter is independent of the gain of the amplifier, so you
can do this procedure with any amplifier gain. Ideally, you set the amplifier
gain (
G
s
) and the amplitude of the sine wave ( V
s
) so that V
s
= 3.4 V
rms
/ G
s
.
You can set V
s
to a lower amplitude, but not a higher one. To prevent errors
due to ripple in the passband, the frequency of the sine wave must be lower
than 1/50th of the cutoff frequency. For this procedure, in sections
SCXI-1141/1142/1143 Before Revision F or SCXI-1141/1142/1143
Revision F or Later you will set the filters to a cutoff frequency of 25 kHz
and use a sine wave of less than 500 Hz.
SCXI-1141/1142/1143 Before Revision F
Complete the following steps to set up the SCXI-1141/1142/1143 for
adjustment and to adjust the AC gain filter, referring to Figures 2 and 3
as needed:
1. Remove the grounding screw from the module.
2. Remove the cover on the module to access the potentiometers.
Figure 2. Grounding Screw and Cover Removal
1 Grounding Screw 2 Module Cover
1
2