1. Foil Element Strain Gage
the ratio between strain and resistance is the gage factor,
for foil gages, F~2
for semiconductor gages, F~ 25 to 50

2. “Quarter” Bridge Circuit
1 of 4 “legs” of the Wheatstone Bridge is a strain gage +
Rgage RA
Vin _ +
Vout V2 + _ + V1 RC RB _ _

3. “Half” Bridge Circuit + R R+DR Vin _ + Vout V2 + _ + V1 R R-DR _ _
2 of 4 “legs” of the Wheatstone Bridge are strain gages + R
R+DR
Vin _ +
Vout V2 + _ + V1 R
R-DR _ _

4. “Full” Bridge Circuit + R+DR R-DR Vin _ + Vout V2 + _ + V1 _ _ R-DR
All 4 “legs” of the Wheatstone Bridge are strain gages +
R+DR
R-DR
Vin _ +
Vout V2 + _ + V1 _ _
R-DR
R+DR

5. Half Bridge Circuit + R+DR R Vin _ + Vout V2 + _ + V1 _ _ R R+DR
Two “legs” of the Wheatstone Bridge are strain gages with same strain, R+DR +
R+DR R
Vin _ +
Vout V2 + _ + V1 _ _ R
R+DR

6. Load Cell w/Differential Amplifier
RED Rf
R+DR
R-DR
Vin + - Ri -
Vin
GREEN
WHITE + Ri V0 Rf
BLACK