External Guided Wave Level Measurement Through Tank Walls

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Solution Overview

Problem

Traditional liquid level measurement systems, particularly in jet fuel applications, are invasive, prone to clogging, and pose safety risks due to electrical energy injection, necessitating a need for improved, non-invasive and intrinsically safe solutions.

Innovation Solution

A non-invasive guided wave sensing system using external guided wave sensors to measure liquid levels by emitting and detecting guided waves through the tank walls, analyzing wave attenuation and mode conversion to determine fuel quantity, without injecting energy into the tank.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional invasive liquid level measurement systems are used, then measurement function is achieved, but reliability deteriorates due to clogging and safety hazards worsen due to electrical energy injection

Engineering Contradiction:

Improvesystem reliabilityVSAvoidclogging and safety hazards

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The measurement system is extracted from the liquid environment and placed outside the tank. Guided wave sensors are mounted on the external surface of the tank wall, allowing measurement without direct contact with the liquid. This eliminates clogging issues and removes electrical components from the hazardous liquid environment, thereby improving reliability and reducing safety hazards.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The tank wall itself serves as an intermediary medium to transmit guided waves from the external sensors to the liquid level measurement point. The guided waves propagate through the tank wall and interact with the liquid level, allowing indirect measurement without direct sensor contact with the liquid. This mediator approach maintains measurement functionality while avoiding the harmful effects of direct invasive contact.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If internal sensors are placed in the liquid, then measurement accuracy is maintained, but device complexity increases and safety risks worsen

Engineering Contradiction:

Improveliquid level measurement accuracyVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Traditional mechanical or electrical contact-based measurement systems are replaced with guided wave acoustic sensing. The guided wave sensors generate and detect acoustic waves that propagate through the tank wall, eliminating the need for complex electrical components, moving parts, or direct mechanical contact with the liquid. This substitution maintains measurement precision while reducing device complexity and safety risks.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If electrical energy is injected into the liquid for measurement, then measurement function is achieved, but safety hazards worsen due to spark risk

Engineering Contradiction:

Improvemeasurement operationVSAvoidspark and ignition risk

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The potentially harmful electrical energy injection is converted into harmless acoustic guided wave energy. Instead of using electrical fields that could create sparks, the system uses mechanical wave energy that propagates through the tank wall. This conversion maintains the measurement function while eliminating the spark and ignition risks associated with electrical energy in flammable liquid environments.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 system provides reliable and safe liquid level measurement by avoiding clogging and safety hazards, ensuring operational integrity and accuracy in harsh environments.

Implementation Method 1

A non-invasive guided wave sensing system using external guided wave sensors to measure liquid levels by emitting and detecting guided waves through the tank walls

Methodology Applied

Scientific EffectGuided wave propagation: Waveguide

Implementation Method 2

determining the height of a liquid level interface in a container from an acoustic signal or echo time measurement

Methodology Applied

Scientific EffectAcoustic echo time measurement: Echo

Implementation Method 3

correlating the attenuation amount of the one or more detected guided waves to a liquid level to determine the liquid level in the liquid container

Methodology Applied

Scientific EffectWave attenuation: Absorption (EM radiation)

Data Source

PatentEP4310464B1Methods and algorithms for liquid level measurement

Publication Date: 2025.11.26 SIMMONDS PRECISION PRODUCTS INC

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AI summary

In accordance with at least one aspect of this disclosure, a method for measuring a liquid level in a liquid container includes, emitting one or more guided waves from a guided wave sensor array through a liquid volume within a liquid container, the guided wave sensor array coupled to the liquid container, detecting the one or more guided waves with at least one of the guided wave sensor array or a second guided wave sensor array, and determining a liquid level of the liquid container using the one or more detected guided waves.