Conductivity Sensor Merging Inductive and Electrode Principles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conductivity sensors are limited in measuring a wide range of electrical conductivity values, particularly failing to accurately record medium value ranges, as they are designed either for high or low conductivity detection.
Innovation Solution
A conductivity sensor and method utilizing an inductive-conductive measuring principle with a first coil, electrodes, and a control and evaluation unit, where the sensor induces a current flow in the liquid medium and measures the voltage drop across electrodes to determine conductivity, accounting for the geometry of the measuring arrangement and correcting for systematic errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conductive conductivity sensors with electrodes are used, then small conductivities can be detected, but large conductivities cannot be accurately measured
Solution Approach 1:
The patent combines inductive and conductive measuring principles into a single sensor system. The sensor includes both a coil for inductive measurement and electrodes for conductive measurement, allowing it to accurately measure conductivity across the entire range from deionized water (low conductivity) to acids and alkalis (high conductivity) by switching between or combining the two measurement methods.
Solution Approach 2:
The conductivity sensor is designed with multi-functionality to perform both inductive and conductive measurements. This universal design enables the single sensor to handle diverse measurement tasks across different conductivity ranges, eliminating the need for separate sensors for different application scenarios.
2Measurement precision
If inductive conductivity sensors are used, then large conductivities can be detected, but small conductivities cannot be accurately measured
Solution Approach 1:
The patent merges inductive and conductive measuring principles in one sensor system. The coil enables accurate measurement of large conductivities through inductive coupling, while the electrodes provide conductive measurement capability for low conductivity applications, achieving full-range measurement coverage.
Solution Approach 2:
The sensor achieves universality by incorporating both inductive and conductive measurement capabilities, allowing it to function effectively across the complete spectrum of conductivity values from deionized water to concentrated electrolytes.
3Measurement precision
If alternating voltage is applied to electrodes to avoid polarization effects, then measurement accuracy improves, but measurement complexity increases
Solution Approach 1:
The patent applies periodic alternating voltage to the electrodes instead of direct current. This periodic action prevents charge accumulation and polarization effects at the electrode-liquid interface, maintaining measurement accuracy. The control unit manages the alternating voltage application and processes the resulting measurements.
Solution Approach 2:
The control and evaluation unit monitors the measurement process and adjusts parameters to minimize polarization effects. By using feedback control, the system maintains measurement accuracy while managing the complexity of applying alternating voltage and processing the measurements.
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
Enables the measurement of a broad range of electrical conductivity values, including those of deionized water to acids or alkalis, with high accuracy and reliability by minimizing polarization effects and accounting for parasitic influences.
Implementation Method 1
the first coil (11), in particular a transmitting coil, for generating a time-varying magnetic field, wherein during operation an electric vortex field is induced in the liquid medium (6) by the first coil (11)
Implementation Method 2
Conductive conductivity sensors measure electrical conductivity by detecting the ohmic resistance of the liquid, based on the current intensity, voltage drop, and geometry of the measuring setup
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A conductivity sensor (1) for measuring the electrical conductivity of a liquid medium (6) is described and illustrated, comprising at least a first coil (11), a current source (9) and a control and evaluation unit (5), wherein the current source (9) is connected to the first coil (11).The task of providing a conductivity sensor capable of determining a particularly large range of electrical conductivity values is solved by additionally providing at least one first electrode (2) and one second electrode (3) and at least one voltage measuring unit (10), wherein the voltage measuring unit (10) is connected to the first electrode (2) and the second electrode (3), wherein the control and evaluation unit (5) is connected to the current source (9) and to the voltage measuring unit (10), and wherein the first electrode (2) and the second electrode (3) are arranged such that they do not have electrical contact with the first coil (11). Furthermore, another conductivity sensor and a method for determining the electrical conductivity of a liquid medium are described and illustrated.