Strain Gage Quarter Bridge (Single Strain Gage In 3-Wire Configuration) - HBM ClipX Bedienungsanleitung

6.6.3

Strain gage quarter bridge (single strain gage in 3-wire configuration)

You can also connect a single strain gage if you add a temperature stable resistor to the
circuit at the ClipX input. The resistor must have the same resistance value as the strain
gage. The 3-wire circuit keeps the zero point stable, but the resistance of the supply
cables and the temperature influence on them changes the signal, because the loss in
the cables to the strain gage is not compensated. So avoid using thin connection wires
if possible. They have a high resistance, and so will cause higher loss and have a
greater temperature effect. Provided cables are not too thin, and cable lengths are kept
to a few meters, the effect is usually negligible. Calculation formulas for the loss can be
found in the literature on strain gage 3-wire circuits.
Abb. 23: Plug terminal X4, example for a strain gage with 350 Ω measuring grid.
ClipX
Electrical connections, LEDs
Pt100
TEDS
S
4
1 Measurement signal +
2' Sense lead −
2 Bridge excitation voltage −
3' Sense lead +
3 Bridge excitation voltage +
Cable shield
AI
I
U
43