Liquid level sensor

A liquid level sensor comprising:

• a substrate having a longitudinal axis;
• a first plurality of thermocouples provided on one side of said substrate in longitudinally spaced relationship;
• a second plurality of thermocouples provided on said one side of said substrate in longitudinally spaced relationship to each other, respective ones of said second plurality of thermocouples being positioned in laterally spaced relationship to respective ones of said first plurality of thermocouples,
• said first and second thermocouples being interconnected in alternating series relationship;
• a heat source for increasing the temperature of each of said plurality of first thermocouples;
• and
• a heat sink provided on said substrate in close proximity to said second plurality of thermocouples;
• said sensor being adapted to be positioned within a vessel containing a volume of liquid with said sensor partially immersed in said liquid such that said first and second thermocouples cooperate to generate a signal indicative of the level of said liquid within said vessel.

A liquid level sensor for use in determining the level of a liquid along the length thereof comprising:

• an elongated substrate;
• a first plurality of thermocouples provided on said substrate in longitudinally spaced relationship;
• a second plurality of thermocouples provided on said substrate in longitudinally spaced relationship, respective ones of said second plurality of thermocouples being laterally spaced from respective ones of said first plurality of thermocouples,
• said first and second thermocouples being interconnected in alternating series relationship;
• a plurality of heating elements, respective ones of said plurality of heating elements being positioned in close proximity to respective ones of said plurality of first thermocouples;
• said plurality of first and plurality of second thermocouples cooperating to generate a signal indicative of the level of liquid along the length of said substrate when said substrate is at least partially immersed in said liquid.

A liquid level sensor for use in providing a signal indicative of the level to which said sensor is submersed in a liquid comprising:

• an elongated substrate having an upper end and a lower end;
• a first series of thermocouples positioned in spaced relationship along the length of said substrate;
• a second series of thermocouples positioned in spaced relationship along the length of said substrate, each of said second series of thermocouples being laterally spaced from a corresponding one of said first series of thermocouples;
• said first and second series of thermocouples being interconnected in alternating series relationship;
• a first electrical lead extending from adjacent said lower end of said substrate to one of said first series of thermocouples located most closely adjacent said upper end of said substrate and a second electrical lead ending from adjacent said lower end of said substrate to one of said second series of thermocouples located most closely adjacent the lower end of said substrate;
• and
• a heat source comprising a plurality of heating elements for heating each of said first series of thermocouples, said heat source having electrical connections located adjacent said lower end of said substrate,
• said first and second series of thermocouples cooperating to provide a signal indicative of the level to which said substrate is submersed in said liquid;
• power supply leads connected to said electrical connections on said substrate to supply power to said heat source and signal transmitting leads electrically connected to said first and second electrical leads to transmit said signal to a remote indicator, said power supply leads and said signal transmitting leads extending away from said substrate so as to thereby avoid transferring liquid to a portion of said substrate above the level at which it is submersed.

A liquid level sensor for use in providing a signal indicative of the level to which said sensor is submersed in a liquid comprising:

• an elongated substrate;
• a first plurality of thermocouples provided on said substrate in longitudinally spaced relationship;
• a second plurality of thermocouples provided on said substrate in longitudinally spaced relationship to each other, respective ones of said second plurality of thermocouples being positioned in laterally spaced relationship to respective ones of said first plurality of thermocouples,
• said first and second thermocouples being interconnected in alternating series relationship;
• a heat source for increasing the temperature of each of said first plurality of thermocouples comprising a plurality of discrete heating elements, respective ones of said plurality of heating elements being positioned in close proximity to respective ones of said plurality of first thermocouples;
• a coating overlying said first and second plurality of thermocouples and said heat source, said coating being operative to resist retention of liquid above said level to which said sensor is submersed in said liquid,
• said first and second plurality of thermocouples cooperating to provide an accurate signal indicative of the level to which said sensor is submersed in said liquid.