A level gauge for detecting process variables related to a distance to a surface of a content in a tank, includes a first and second functionally independent circuitry arrangements comprising transceiver circuitry and processing circuitry. The gauge further comprises a power divider providing isolation between signals having the same propagation mode, a single wire transmission line probe, and a matching arrangement providing an electrically matched connection between the electrical connection of a process seal and the single wire transmission line probe. A combination of a power divider with a matching arrangement allows multiple channels on one single wire transmission line probe.