US Patent 7498974 Radar level gauge with a galvanically isolated interface

A radar level gauge (RLG) using electromagnetic waves for determining a process variable of a product in a tank is provided which includes timing circuitry adapted to provide timing control of a transceiver, and a communication interface arranged to receive power in an intrinsically safe manner and to connect the radar level gauge externally thereof. The RLG further comprises an isolation interface arranged to galvanically isolate the transceiver from the timing circuitry and the communication interface, the isolation interface being arranged to transfer power and timing control from the timing circuitry and the communication interface to the transceiver circuitry.