With the 2-wire circuit, the strain gauges and the amplifier are connected via two wires. The circuit diagram shows that the cable resistance is added twice (feed and return) to the strain gauge resistance.
This affects both the bridge's zero point and its sensitivity. Even with cables with lengths of few centimeters it is essential to allow for the cable resistance. The 2-wire circuit is particularly sensitive to temperature variation during measurement, since the change in resistance immediately affects the measured value.
The 2-wire circuit's temperature stability has been tested using installed strain gauges and the QuantumX MX1615 strain gauge bridge amplifier.