©
National Instruments Corporation
39
SCC-SG Series Strain-Gauge Modules User Guide
6.
Locate the shunting resistor and replace it. Refer to Figure 30 to locate
the shunting resistor on the SCC-SG11.
Figure 30.
SCC-SG11 Parts Locator Diagram
Using the SCC-SG
XX
This section provides information about how to ensure your readings are
properly scaled and converted to the correct units.
Converting Voltage Measurements to Units of Strain
Once you have acquired the voltage signal
V
CH
, you can scale this voltage
to the appropriate strain units in software. This is done automatically for
you in traditional NI-DAQ using the strain virtual channel and in
NI-DAQmx using a strain task or global channel. You also can scale the
voltages manually in your application using the voltage to strain conversion
equations provided in this document for each configuration type.
Finally, there are voltage to strain conversion functions included in
LabVIEW, traditional NI-DAQ, and NI-DAQmx. In LabVIEW, the
conversion function,
Convert Strain Gauge Reading.vi
, is in the
Data Acquisition»Signal Conditioning
subpalette. For text based
programming ADEs, the prototypes for the NI-DAQ functions,
Strain_Convert
and
Strain_Buf_Convert
, are in the header file
convert.h
for C/C++, and
convert.bas
for Visual Basic. Refer to the
Traditional NI-DAQ User Manual
and the
LabVIEW Measurements
Manual
for more information.
1
R1 Shunting Resistor Connected
to Pins 3 and 4
2
R4 Shunting Resistor Connected
to Pins 1 and 2
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