Printed Level Sensor Label with Resonant Tank Circuit
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Solution Overview
Problem
Existing level sensing systems for containers face challenges in accurately measuring material levels due to sensitivity issues and measurement uncertainty, particularly when using capacitive and inductive elements in series, which can be affected by the proximity of the reader coil and container geometry.
Innovation Solution
A disposable passive electronic level sensor label is created using printed capacitive and inductive elements, with a resonant tank circuit design that includes a less sensitive load coil to reduce measurement uncertainty, and can be integrated into the container or attached to its surface, utilizing near-field coupling for remote measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a capacitive and inductive element arrangement is used for level sensing, then measurement capability is provided, but measurement precision deteriorates due to sensitivity to reader coil proximity and container geometry
Solution Approach 1:
The patent introduces a resonant tank circuit as an intermediary between the capacitive/inductive elements and the reader coil. This resonant circuit acts as a mediator that couples the sensor elements to the reader, reducing direct sensitivity to reader coil proximity and container geometry variations, thereby improving measurement precision and reliability
Solution Approach 2:
The patent changes the operating parameters by tuning the resonant frequency of the tank circuit to match the reader coil frequency. This parameter matching creates a resonant coupling condition that enhances signal strength while reducing sensitivity to positional variations, thus improving measurement precision
2Ease of manufacture
If printed capacitive and inductive elements are used, then manufacturing cost is reduced, but measurement precision may deteriorate due to printing tolerances
Solution Approach 1:
The patent compensates for printing tolerances by optimizing the resonant frequency parameters of the tank circuit. By carefully selecting the capacitance and inductance values to achieve a specific resonant frequency, the system becomes less sensitive to variations in element geometry caused by printing processes, maintaining measurement precision while keeping manufacturing costs low
3Measurement precision
If a less sensitive load coil is used in the resonant tank circuit, then measurement uncertainty is reduced, but inductive coupling efficiency may deteriorate
Solution Approach 1:
The patent optimizes the inductance value of the load coil to achieve a balance between sensitivity and coupling efficiency. By selecting an inductance value that creates an optimal resonant condition with the capacitive elements, the system reduces measurement uncertainty while maintaining sufficient coupling efficiency for reliable operation
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
This solution provides accurate and reliable material level monitoring with reduced measurement uncertainty, allowing for precise detection of changes in capacitance and resonant frequency, even in flexible containers like plastic bags, and can be produced at a low cost using printing operations.
Implementation Method 1
a capacitive structure configured to be associated with the container... precise detection of changes in capacitance
Implementation Method 2
a first inductive element arrangement... and a second inductive element arrangement... precise detection of changes in resonant frequency
Implementation Method 3
utilizing near-field coupling for remote measurement
Data Source
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AI summary
The level sensor system includes a level sensor label configured to be associated with a container containing a material whose level is to be sensed, the level sensor label arrangement having a circuit which includes an inductive element electrically connected to a capacitive structure configured to be associated with the container.