Feasibility of a Planar Coil-Based Inductive-Capacitive Water Level Sensor with a Quality-Detection Feature: An...

Area of Science:

• Electrical Engineering
• Environmental Monitoring
• Sensor Technology

Background:

• Accurate water level and quality monitoring are essential for efficient water and wastewater management.
• Existing sensors often measure only one parameter, necessitating multiple devices for comprehensive analysis.
• A single sensing element capable of providing both water quantity and quality data is highly desirable.

Purpose of the Study:

• To develop and validate a novel water-level-sensing mechanism based on planar coils.
• To enable simultaneous detection of water level and conductivity (quality) using a single sensing element.
• To provide a scalable solution for integrated water quantity and quality assessment.

Main Methods:

• Fabrication of planar coils on a printed circuit board (PCB).
• Utilizing eddy current induction within the water column to alter coil inductance and capacitance.
• Measuring sensor coil reactance at a low frequency for level detection and at resonance for conductivity measurement.

Main Results:

• The sensor reliably determines water level by measuring coil reactance at a frequency significantly below resonance.
• Simultaneously, measurement at resonance using an inductance-to-digital converter accurately indicates water conductivity, serving as a quality indicator.
• Laboratory testing confirmed the sensor's capability for dual-parameter sensing.

Conclusions:

• A single, planar coil-based sensor can effectively measure both water level and quality.
• This integrated sensing approach offers a beneficial solution for water and wastewater management.
• The developed PCB sensor technology is scalable and demonstrates practical application potential.