Abstract: A transducer for determining the liquid level within a container that is subjected to at least partial solidification at or below a freezing temperature is provided. The transducer includes a mounting head adapted for connection to the container, a liquid level sensor adapted for extending into the container from the mounting head; and a heating unit extending through the mounting head. The heating unit is constructed of at least one tubular member that surrounds or encircles the liquid level sensor. Heated fluid from a fluid source is circulated through the at least one tubular member for heating the contents of the tank at least within the vicinity of the liquid level sensor. A fluid withdrawal tube can also be in close proximity to the at least one tubular member so that the contents of the tank surrounding the heating unit can be removed even when the remaining tank contents are in a frozen state.