This is simple Bridge Circuit Diagram With One Power Supply. For systems with only one power supply, two op amps act as instrumentation and buffer amps. The OPA111 AM buffers the reference mode of the bridge and applies that voltage to the instrumentation amps ref terminal. Output is taken between the amplifier outputs to exclude the fixed output offset.
The additional op amp creates a bridge error of 2, where IB=bias current of op amp and R is the resistance of one leg of the bridge.