A Time Domain Return measurement system for measuring liquid level, linear movement or other measurements which includes a first and second electrode, the second electrode spaced from the first electrode to define a gap, and an electronics assembly connected to the first and second electrodes equipped with a generator for transmitting an electromagnetic signal for propagation along the electrodes. The signal generator has a first analog timing circuit for actuating a slow-rising function of voltage versus time, a second analog timing circuit associated with the first analog timing circuit for actuating a fast-rising function of voltage versus time, and a receive circuit electrically connected to the electrodes, the receive circuit being activated for receiving return echo data associated with the electromagnetic signal transmitted when the fast-rising function is equal or greater than the slow-rising function to determine the position of the second medium with respect to the electrodes.