Combination Electrode Extended Reference Chamber
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional combination electrodes, such as pH combination electrodes, suffer from limited service life due to KCl leakage, which leads to erroneous measurements, especially in miniaturized designs where small changes in KCl concentration significantly affect electrochemical potential.
Innovation Solution
A combination electrode design featuring an inner and outer tube with a hydrogel diaphragm that swells to seal the reference chamber, allowing a larger volume of conductive fluid, reducing leakage and maintaining stable electrolyte concentration, thereby extending the service life and ensuring error-free measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a miniaturized combination electrode design is used, then the device size is reduced and portability is improved, but the service life is limited due to KCl leakage causing concentration changes
Solution Approach 1:
The reference chamber is divided into two separate chambers: a first reference chamber and a second reference chamber. This segmentation allows each chamber to have its own KCl solution reservoir, preventing cross-contamination and concentration changes that would occur with leakage in a single chamber design. The separation maintains stable electrochemical potential while enabling miniaturization.
Solution Approach 2:
The first reference chamber is positioned inside the second reference chamber, creating a nested structure. This nesting allows the electrode to maintain a compact, miniaturized form factor while providing sufficient volume for KCl solution in both chambers. The inner chamber contains its own KCl reservoir, ensuring stable concentration even when the outer chamber's KCl leaks or depletes.
2Reliability
If the KCl solution volume is increased to prevent concentration changes, then measurement stability is improved, but the electrode volume increases
Solution Approach 1:
The KCl solution is divided between two separate reference chambers instead of requiring a large single chamber. Each chamber contains its own KCl reservoir, so the total KCl volume is distributed across multiple smaller compartments. This segmentation provides measurement stability through sufficient KCl volume while maintaining a compact overall electrode size.
Solution Approach 2:
The nested chamber structure allows one reference chamber to be positioned inside another, maximizing the use of internal volume. This nesting enables the electrode to contain adequate KCl solution volume for stable measurements without increasing the external dimensions of the electrode, thus maintaining miniaturization while improving reliability.
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
The design significantly extends the service life of combination electrodes by minimizing changes in electrolyte concentration, allowing for longer periods of accurate pH measurements without errors.
Implementation Method 1
The combination pH electrode has a diaphragm, preferably a hydrogel, in the region of the first outer tube longitudinal end... said diaphragm being designed to keep the second electrically conductive fluid in the reference chamber
Implementation Method 2
a through-hole, which is situated in the inner tube between the first seal and the second inner tube longitudinal end and fluidly connects the reference chamber to an extended reference chamber
Data Source
AI summary
A pH combination electrode includes inner and outer tubes, working and reference electrodes, and a hydrogel diaphragm between the tubes. A seal is disposed inside the inner tube closer to a first inner tube end than to the second inner tube end. An extended reference chamber is formed inside the inner tube between the seal and the second inner tube end. A first conductive fluid is contained in the inner tube between the seal and the first inner tube end. A second conductive fluid is contained in the extended reference chamber and in a reference chamber formed between the inner and outer tubes. A through-hole in the inner tube allows the second conductive fluid to flow between the reference chamber and the extended reference chamber. The working electrode extends into the inner tube, through the seal and into the first conductive fluid. The reference electrode contacts the second conductive fluid.