The circuit is used in many AC current sensing applications. Basically current is sensed with a 10A current transformer (called CT) and it’s signal is rectified through precision rectifier. The output is DC voltage which is then fed into MCU ADC.
This circuit, along-with voltage sensing circuit, can be used to measure power. For example it may be a part of intelligent power socket which measures the power running through an attached load. The intelligent power socket can shut down (turn off itself) on pre-programmed power outage or current threshold. The power socket may also inform a remote unit about the power status, periodically or upon request.