Measuring instrument that senses heat transfer along a probe
First Claim
1. A measuring instrument that senses heat transfer along a probe that is inserted at least partially into an environment, the heat transfer occurring between the probe and the environment, comprising:
- a main probe unit having first and second legs disposed in a side-by-side spaced apart substantially parallel relationship;
a heater circuit having a heater segment for heating at least said first leg of said main probe unit and being disposed in an orientation extending along said first leg;
heated sensor means disposed in sid first leg in positions proximate to said heater segment for being heated by said heater segment and for sensing temperatures at a plurality of positions along said first leg;
second sensor means disposed in said second leg in a position for sensing temeratures at a plurality of positions along said second leg; and
circuit means connected to said heated sensor means and said second sensor means for producing an output signal proportional to the temperatures sensed by said heated sensor means and said second sensor means whereby the output signal is proportional to the heat transfer measured along the probe and is an indication of environmental conditions.
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Accused Products
Abstract
A measuring instrument includes a U-shaped probe that senses temperature and is useful for sensing the level of a liquid in a tank. A main probe unit has first and second legs disposed in a side-by-side, parallel relationship and a heater cable is contained within and along the length of the first leg. Heated sensors are disposed inside the first leg in positions proximate to the heater cable for sensing temperatures at a plurality of positions along the first leg, and non-heated sensors are disposed in the second leg for sensing temperatures at a plurality of positions along the second leg. An electrical circuit is connected to the heated temperature sensors and the non-heated temperature sensors for producing at least one signal indicating the temperatures of the heated sensors and preferably indicating the temperatures of the heated sensors relative to the non-heated sensors.
51 Citations
15 Claims
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1. A measuring instrument that senses heat transfer along a probe that is inserted at least partially into an environment, the heat transfer occurring between the probe and the environment, comprising:
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a main probe unit having first and second legs disposed in a side-by-side spaced apart substantially parallel relationship; a heater circuit having a heater segment for heating at least said first leg of said main probe unit and being disposed in an orientation extending along said first leg; heated sensor means disposed in sid first leg in positions proximate to said heater segment for being heated by said heater segment and for sensing temperatures at a plurality of positions along said first leg; second sensor means disposed in said second leg in a position for sensing temeratures at a plurality of positions along said second leg; and circuit means connected to said heated sensor means and said second sensor means for producing an output signal proportional to the temperatures sensed by said heated sensor means and said second sensor means whereby the output signal is proportional to the heat transfer measured along the probe and is an indication of environmental conditions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A measuring instrument that senses heat transfer along a probe that is inserted at least partially into an environment, the heat transfer occurring between the probe and the environment, comprising:
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a metallic tubular sheath having a U-shape with two parallel side-by-side upright spaced apart legs, said legs having top ends and bottom ends, and a lower transverse connecting segment connecting the bottom ends of said legs; a heater circuit having a heater cable segment disposed in and along the length of said first leg; an electrical insulator disposed inside said sheath, having an elongate heater passageway disposed at least in said first leg for receiving said heater circuit and having a plurality of elongate sensor passageways extending through said first leg, said connecting segment and said second leg; a first sensor wire extending through said one of said sensor passageways from the top end of said first leg to the top end of said second leg, said first sensor wire having a heated thermocouple junction disposed in said first leg and a non-heated thermocouple junction disposed in said second leg at a position perpendicularly across from the heated thermocouple junction, a voltage potential being produced across said first sensor wire that is proportional to the temperature of said heated thermocouple junction relative to the temperature of said non-heated thermocouple junction; at least a second sensor wire extending through one of said sensor passageways from the top end of said first leg to the top end of said second leg, said sensor wire having a heated thermocouple junction disposed in said first leg at a position along said first leg different from the position of said heated thermocouple junction of said first sensor wire and having a non-heated thermocouple junction disposed in said second leg perpendicularly across from said heated thermocouple junction of said second sensor wire, a voltage potential being produced across said second sensor wire that is proportional to the temperature of said heated thermocouple junction of said second sensor wire relative to the temperature of said non-heated thermocouple junction thereof; and circuit means connected to said first and second sensor wires for producing an output signal indicating the voltage potentials produced by said first and second sensor wires. - View Dependent Claims (11)
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12. A measuring instrument that senses heat transfer along a probe inserted at least partially into a liquid in a vessel to measure to the level of the liquid, comprising:
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a metallic tubular sheath having a U-shape with two parallel side-by-side upright spaced apart legs for being disposed vertically in a vessel, said legs having top ends and bottom ends, and a lower transverse connecting segment connecting the bottom ends of said legs; a heater circuit having a heater cable segment disposed in and along the length of at least said first leg; an electrical insulator disposed inside said sheath, having an elongate heater passageway disposed at least in said first leg for receiving said heater circuit and having a plurality of elongate sensor passageways extending through said first leg, said connecting segment and said second leg; a first sensing wire extending through one of said sensor passageways from the top end of said first leg to the top end of said second leg, said first sensor wire including a first elongate resistor extending along at least a portion of the length of said first leg and having a resistance that varies with the temperature of said first elongate resistor for sensing liquid levels at a plurality of positions vrtically along said first leg; a second sensor wire extending through one of said sensor passageways from the top end of said first leg to the top end of said second leg, said second sensor wire including a second elongate resistor extending along at least a portion of the length of said second leg and having a resistance that varies with the temperature of said second elongate resistor for sensing ambient temperatures at a plurality of positions vertically along said second leg; and circuit means connected to said first and second elongate sensor wires for producing at least one output signal indicating the resistances of said first and second sensor wires. - View Dependent Claims (13, 14, 15)
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Specification