Transcript No Slide Title

Foil Element Strain Gage
► the
ratio between strain
and resistance is the
gage factor,
R
R
F
L
L
R
R or R  F

R
for foil gages, F~2
 for semiconductor gages, F~ 25 to 50

“Quarter” Bridge Circuit
1 of 4 “legs” of the Wheatstone Bridge is a strain gage
+
Rgage
RA
Vin
+ V
out
_
+
+
V1
_
_
RB
RC
V2
_
“Half” Bridge Circuit
2 of 4 “legs” of the Wheatstone Bridge are strain gages
+
Vin
_
+ V
out
+
V1
_
R+R
R
_
+
R
R-R_
V2
“Full” Bridge Circuit
All 4 “legs” of the Wheatstone Bridge are strain gages
+
Vin
_
+ V
out
+
+
V1
_
R+R
R-R
_
R+R
R-R _
V2
Half Bridge Circuit
Two “legs” of the Wheatstone Bridge are strain gages
with same strain, R+R
+
R+R
R
Vin
_
+ V
out
+
+
V1
_
_
V2
R+R
R
_
Load Cell w/Differential Amplifier
RED
Rf
+
R-R
R+R
Ri
-
VV
in
in
GREEN
WHITE
R+R
-
BLACK
R-R
+
Ri
V0
Rf