Frit-less pH Measurement Using Differential Electrode Signals
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Solution Overview
Problem
Conventional pH measurement electrodes require frequent maintenance, calibration, and are prone to errors due to internal reference solution evaporation, frit fouling, and fragility, leading to increased costs and reduced sensitivity.
Innovation Solution
A frit-less and internal solution-free pH measurement system using electrodes sensitive to interferants and pH, with a differential measurement approach employing Sp2 and Sp3 carbon materials or metallic systems to subtract interferant signals from overall measurements, eliminating the need for a frit and internal reference solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional pH measurement electrodes with internal reference solution and frit are used, then pH measurement can be performed, but frequent maintenance and calibration are required due to internal reference solution evaporation and frit fouling
Solution Approach 1:
The patent removes the internal reference solution and frit from the pH electrode design. By extracting these components that require maintenance, the electrode becomes a simple solid contact electrode that measures pH directly through surface reactions, eliminating evaporation and fouling issues
Solution Approach 2:
The patent employs a disposable solid contact electrode that does not require long-term maintenance. The electrode is designed for use and replacement rather than prolonged service, eliminating the need for calibration and maintenance procedures associated with traditional electrodes
2Measurement precision
If conventional pH electrodes with frit and internal reference solution are used, then pH measurement is possible, but errors occur due to frit fouling and reference solution changes
Solution Approach 1:
The patent extracts the frit and internal reference solution from the measurement system, eliminating the sources of measurement errors. The solid contact electrode provides a stable, fouling-free measurement interface that maintains consistent accuracy without the reliability issues of traditional designs
3Reliability
If conventional pH electrodes are used, then pH measurement can be performed, but costs increase due to frequent maintenance and calibration
Solution Approach 1:
The patent employs a low-cost disposable solid contact electrode that eliminates expensive maintenance and calibration requirements. The simple design without internal reference solutions or frits reduces both material costs and operational expenses
Solution Approach 2:
The solid contact electrode requires no external reference solution or maintenance procedures. It operates autonomously through surface-based pH measurement, eliminating the need for costly calibration solutions and maintenance activities
4Measurement precision
If conventional pH electrodes are used, then pH measurement is possible, but sensitivity is reduced due to frit resistance and internal solution issues
Solution Approach 1:
The patent removes the frit and internal reference solution that impede sensitivity. The direct solid contact measurement interface provides superior electrical contact and pH response without the signal attenuation caused by frit resistance
Solution Approach 2:
The patent employs composite solid contact materials that enhance pH sensitivity through surface chemistry optimization. The composite structure provides both electrical conductivity and pH-responsive surface properties for high sensitivity 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
This solution reduces maintenance requirements, minimizes errors, and maintains sensitivity by accurately measuring pH without a frit or internal reference solution, providing reliable and cost-effective pH measurements.
Implementation Method 1
measuring an electrical potential in a volume of aqueous sample
Implementation Method 2
a second electrical potential associated with both the interferants and a pH of the aqueous sample is measured across a second electrode and the reference electrode. The electrical potential associated with the interferants of the aqueous sample is subtracted from the electrical potential associated with both the interferants and the pH
Data Source
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AI summary
Method and apparatus for measuring pH in an aqueous sample with a frit-less electrode, including: introducing an aqueous sample into a measurement device comprising at least three electrodes, wherein at least one electrode of the at least three electrodes comprises a ground rod electrode, wherein at least one electrode of the at least three electrodes comprises a first measurement electrode, preferably a sp3 boron doped diamond electrode, that is interferant sensitive and pH insensitive, and wherein at least one electrode of the at least three electrodes comprises a second measurement electrode, preferably a sp2/sp3 boron doped diamond electrode, that is pH and interferant sensitive; measuring a first electrical potential between the first measurement electrode and the ground rod electrode in the aqueous sample; measuring a second electrical potential between the second measurement electrode and the ground rod electrode in the aqueous sample; and identifying a pH of the aqueous sample based upon a difference between the first electrical potential and the second electrical potential.