Ion Selective Electrode Sensor Signal Drift Reduction
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Solution Overview
Problem
Ion selective electrodes suffer from signal drift issues due to the complexity of internal electrochemical reference compositions, making it difficult to maintain stability and accuracy in ion concentration measurements.
Innovation Solution
An ion selective electrode sensor design featuring a housing with an internal metal salt solution, a woven mesh fabric sieve, and ion-sensitive film layers, along with an Ag/AgCl wire immersed in a KCl solution separated by a porous frit, which stabilizes the electrochemical reference and enhances ion exchange.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an internal electrochemical reference element (Metal/Metal Salt composition) is used to increase ISE signal stability, then the stability of the ISE signal is improved, but the device complexity and manufacturing difficulty increase significantly
Solution Approach 1:
The patent extracts and eliminates the complex internal electrochemical reference element (Metal/Metal Salt composition) from the ISE sensor design. Instead, it uses a simplified reference electrode system with a porous frit separator and KCl solution, removing the problematic components while maintaining the essential reference function.
Solution Approach 2:
The patent introduces a porous frit as an intermediary component between the internal solution and the reference electrode. This porous frit allows ionic conduction while preventing direct mixing, providing a simple yet effective reference system without requiring complex Metal/Metal Salt compositions.
2Measurement precision
If a solid state ISE with internal electrochemical reference element is used, then the ISE probe drift is reduced initially, but the signal drifts unpredictably over time making compensation difficult
Solution Approach 1:
The patent removes the internal electrochemical reference element that causes unpredictable drift over time. By eliminating this component and using a simpler reference electrode system with porous frit, the patent achieves long-term signal stability without the drift problems associated with solid state ISEs containing Metal/Metal Salt compositions.
3Reliability
If conventional ISE production methods are used, then the internal electrochemical reference can be produced, but the production process becomes very complicated
Solution Approach 1:
The patent eliminates the complex production requirements for internal electrochemical reference compositions (Metal/Metal Salt equimolar concentrations). Instead, it uses a simple reference electrode system that can be manufactured without precise compositional control, dramatically simplifying the production process while maintaining reference functionality.
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 configuration reduces signal drift and simplifies the production of the internal electrochemical reference, providing a more stable and accurate measurement of ion concentrations.
Implementation Method 1
at least one ion sensitive film layer on the at least one mesh fabric sieve
Implementation Method 2
internal reference electrode comprised of Ag/AgCl wire in a tube with KCl solution
Implementation Method 3
providing the tube with a porous frit
Data Source
AI summary
An ion selective electrode sensor includes a housing containing an internal solution and enclosing a reference element containing a metal salt solution; open mesh fabric sieves traversing an opening in the housing; and at least one ion sensitive film layer on the mesh fabric sieves.