An intermediate device for supporting a power transfer to an electromagnetic load (505) from a power transmitter (201) comprises a resonance circuit (507) including an inductor (801) and a capacitor (803) where the inductor (801) is arranged to couple to the power transmitter (201) through a first surface area (509) and to the electromagnetic load (505) through a second surface area (511). The resonance circuit (507) is arranged to 5 concentrate energy of the power transfer electromagnetic signal from the first surface area (509) towards the second surface area (511). The device further comprises a communicator (807) for exchanging messages with the power transmitter (201). The communicator (807) transmits a request message to the power transmitter (201) comprising a request for the power transmitter (201) to generate a measurement electromagnetic signal. A load indication 10 processor (813) determines a load indication indicative of a loading of the measurement electromagnetic signal and a detector (815) detects a presence of the electromagnetic load in response to the load indication.