An RF power delivery diagnostic system is provided herein. The system comprises an RF power source (303), an impedance matching network (305), a plasma reactor (307) in electrical contact with the RF power source by way of the impedance matching network, a first RF sensor (309) adapted to measure at least one attribute of the RF power input to the impedance matching network, and a second RF sensor (311) adapted to measure at least one attribute of the RF power output by the impedance matching network.