Omega Engineering OMB-DBK-34A, User Manual

Page: 172 / 250

Half Bridge,
(
∆
R1
↓
and
∆
R2
↑
)
⇒ ∆
E
OUT
↑
)
Resistor Configuration for DBK16
The half bridge configuration makes use of two elements of the strain gage. When using a half bridge external strain gage
(two of four elements), the following applies to the DBK16 on board resistor configuration:
Upper Channel – R10 and R13 are to be installed.
Lower Channel – R22 and R25 are to be installed.
Note that other Half Bridge scenarios exist. The one illustrated applies to the equation:
∆
R1
↓
and
∆
R2
↑
)
⇒ ∆
E
OUT
↑
3-Wire, Quarter-Bridge, Negative (
∆
R
↑⇒ ∆
E
OUT
↑
) for DBK16
The quarter-bridge configuration makes use of one element of the strain gage. The three-wire, quarter-bridge can be
configured as “positive” or “negative.” The above figure represents the negative (minus) configuration. In this setup, the
magnitude of voltage out is directly proportional to the change in resistance
(
∆
R
↑⇒ ∆
E
OUT
↑
). When using a quarter-bridge
external strain gage in the “negative” configuration, the following applies:
Upper Channel – R10 and R11 are to be installed.
Lower Channel – R22 and R23 are to be installed.
An external BCR is to be placed in the –EXC to R1 line (see previous figure).
DBK16, pg. 4
879895
DBK Option Cards and Modules