Campbell Scientific CR9000X Measurement and Control System - Manual (Page 324)

Section 8. Processing and Math Instructions
BrConfig: The BrConfig parameter can be entered as a negative number in
order to change the polarity of the output.
1/4 BRIDGE STRAIN
¼ BRIDGE STRAIN CASE 1
If one of Campbell Scientific's 4WFBXXX Terminal Input Modules is utilized,
the bridge set-up is as depicted in Case 1. For this set up, a negative Option (-
1) should be used in order for the CR9000X to output positive strain values
when the strain gauge experiences positive strain.
¼ BRIDGE STRAIN CASE 2
If the excitation voltage polarity is reversed, or the output polarity is reversed,
or if the bridge is configured as shown in Case 2, then a positive Code (1)
should be used in order for the CR9000X to output positive strain values when
the strain gauge experiences positive strain.
1/2 BRIDGE STRAIN
If one of Campbell Scientific's 4WFBXXX Terminal Input Modules is utilized
with the G2 gauge wired to positive excitation and the G1 gauge wired to
ground, then the bridge set-up is as depicted above. For this set up, a negative
Option should be used in order for the CR9000X to output positive strain values
when the G1 strain gauge experiences positive strain.
8-38