Campbell CR800 Series, Operator'S Manual

Page: 334 / 598

Section 8. Operation
334
Resistive-Bridge Circuits with Voltage Excitation
Resistive-Bridge Type and
Circuit Diagram
CRBasic Instruction and
Fundamental Relationship
Relational Formulas
Four-Wire Half-Bridge
1,3
CRBasic Instruction: BrHalf4W()
Fundamental Relationship
2
:
Full-Bridge
1,3
CRBasic Instruction: BrFull()
Fundamental Relationship
2
:
These relationships apply to BrFull()
and BrFull6W() .
Six-Wire Full-Bridge
1
CRBasic Instruction: BrFull6W()
Fundamental Relationship
2
:
1
Key: V
x
= excitation voltage; V
1
, V
2
= sensor return voltages; R
f
= fixed , bridge or completion resistor; R
s
= variable
or
sensing
resistor.
2
Where X = result of the CRBasic bridge measurement instruction with a multiplier of 1 and an offset of 0.
3
See the appendix Resistive Bridge Modules
(p. 564)
for a list of available terminal input modules to facilitate this
measurement.