Capacitive Sensor Probe for Debris-Tolerant Fluid Level Detection
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Solution Overview
Problem
Existing sensors, such as float-based level sensors and capillary sensors, face challenges in deep frying environments due to debris, viscosity changes, and sanitation issues, leading to inaccurate fluid level detection and potential sensor failure.
Innovation Solution
A capacitive sensor probe that operates across a wide range of fluid viscosities and temperatures, using capacitance to determine the presence and level of fluid, integrated with a control system to prevent heating system operation when insufficient fluid is present, ensuring safe and reliable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If float-based level sensors are used to detect fluid level, then the sensor structure is simple, but the sensor becomes stuck due to debris in the fluid
Solution Approach 1:
The patent replaces the mechanical float-based level sensing system with a capacitive sensing system. The capacitive sensor detects fluid level through electrical field interaction with the fluid, eliminating mechanical components that can become stuck on debris. This substitution maintains simple device structure while significantly improving reliability in debris-containing environments.
2Device complexity
If capillary sensors are used to detect fluid level, then the sensor structure is simple, but the sensor fails when fluid viscosity is high or fluid is partially solid
Solution Approach 1:
The patent replaces the capillary action-based mechanical sensing system with a capacitive sensing system. Capacitive sensing measures electrical properties of the fluid rather than relying on fluid movement or capillary action, enabling it to accurately detect fluid level across a wide range of viscosities including partially solid states, thereby improving adaptability while maintaining simple structure.
3Reliability
If capillary sensors are used in fluid level detection, then the sensor can detect fluid presence, but fluid is retained in the capillary creating sanitation issues
Solution Approach 1:
The patent replaces the capillary tube structure with a capacitive sensing element that detects fluid level through electrical field interaction without requiring fluid to enter or fill a physical cavity. This eliminates the fluid retention problem that creates sanitation issues while maintaining reliable fluid level detection capability.
4Reliability
If capillary sensors are used in temperature-changing environments, then the sensor can detect fluid level, but air pockets expand causing sensor failure
Solution Approach 1:
The patent replaces the capillary tube containing air pockets with a capacitive sensing system that measures electrical properties directly. This eliminates the air pockets that expand with temperature changes and cause sensor failure, while maintaining accurate fluid level detection across varying temperature conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The capacitive sensor provides reliable and sanitary fluid level detection, preventing heating system malfunctions and ensuring safe operation across varying fluid conditions, from partially solid to low viscosity, while maintaining cleanliness and durability.
Implementation Method 1
the capacitive sensor probe determines capacitance of the fluid that surrounds the sensor
Data Source
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AI summary
A capacitive sensor includes a metal radiator disposed at an extreme end of a sensor assembly. A coaxial electrode is electrically interconnected to the metal radiator. The coaxial electrode has a center conductor, a dielectric around the center conductor, and an outer conductor, the center conductor being in electrical continuity with the metal radiator. An insulator configured to fit adjacent the metal radiator is configured to electrically and thermally isolate the metal radiator from selected electrical and thermal properties in an environment wherein the capacitive sensor probe is disposed. A connector is disposed distal from the metal radiator on the coaxial electrode, a portion of the connector being in electrical continuity with the metal radiator.