A liquid level sensing arrangement using a probe uses a baseline probe
circuit characteristic, e.g., a circuit resistance or voltage, that is
measured when the probe is out of contact with the liquid in the tank.
The baseline characteristic may be used to determine a liquid level in
the tank, e.g., a determination whether the liquid level is below or
at/above the probe. In one embodiment, the baseline characteristic may be
compared to a circuit characteristic that is measured as the tank is
being filled. A difference between the baseline characteristic and the
other circuit characteristic may be used to determine whether or not the
probe is in contact with the liquid.