Electrochemical Gas Sensor Vent Membrane for Counter Electrode Gas Release
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Solution Overview
Problem
Existing electrochemical gas sensors face issues with gas venting mechanisms that lead to operational degradation, erroneous readings, and unsafe conditions due to oxygen generated at the counter electrode, which can cause pressure differentials, humidity, and condensation, leading to short circuits and instrument errors.
Innovation Solution
An improved venting system with a vent membrane positioned over the counter electrode and a vent conduit, using synthetic polymers with defined porosity and supported by solid features to prevent deformation, allowing controlled gas release and maintaining pressure balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gas is vented directly from the counter electrode without a membrane, then gas release is simple, but pressure differentials and humidity cause operational degradation and short circuits
Solution Approach 1:
A vent membrane is introduced as an intermediary component between the counter electrode and the external environment. The membrane selectively allows generated gas to pass through while maintaining pressure balance and preventing harmful moisture ingress, thereby improving reliability without excessive complexity
Solution Approach 2:
The vent membrane is implemented as a thin film structure that provides selective permeability. This thin film allows gas molecules to pass through while maintaining structural integrity and pressure equilibrium, solving the reliability issue with minimal added complexity
2Manufacturing precision
If a vent membrane is positioned over the counter electrode, then gas flow is controlled and pressure balance is maintained, but the membrane may deform affecting performance
Solution Approach 1:
Solid support features are strategically positioned at specific locations beneath the vent membrane to provide localized structural reinforcement. This allows the membrane to maintain its selective permeability function while preventing deformation in critical areas, achieving both precise gas flow control and structural stability
3Reliability
If oxygen generated at the counter electrode is not vented, then sensor structure is simple, but pressure differentials cause erroneous readings and safety issues
Solution Approach 1:
The harmful oxygen gas generated at the counter electrode is extracted and removed from the sensor system through the vent membrane. This prevents pressure differentials and safety issues while the membrane's selective permeability ensures controlled removal without introducing excessive complexity
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 solution effectively vents gases generated at the counter electrode, preventing operational degradation and ensuring accurate readings while maintaining sensor durability and safety.
Implementation Method 1
a portion of the vent membrane overlaps with an extended portion of the counter electrode, thereby defining a passage for oxygen generated at the counter electrode to flow through the extended portion into the vent membrane
Implementation Method 2
the vent membrane comprises a synthetic polymer having a porosity within a defined range and a water ingress pressure within a defined range
Data Source
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AI summary
An electrochemical gas sensor (100, 200, 300) comprising: a housing (202, 204) including: a gas sensor cap (214), a gas inlet capillary (310) defined as a channel that passes through the gas sensor cap, an electrolyte (108), a sensor electrode (222), and a counter electrode (228, 700) configured to generate a gas during use of the electrochemical gas sensor, wherein a portion of the housing comprises an aperture (306) through at least one surface of the housing, the aperture dimensioned and configured to prevent water ingress to the electrochemical gas sensor and allow gas egress from the electrochemical gas sensor (100, 200, 300); a plurality of solid features (408) molded within at least one surface of the gas sensor cap (214), the plurality of solid features (408) configured and dimensioned to form support pillars about a vent membrane (252) so as to prevent deformation of the vent membrane (252) during assembly and use of the electrochemical gas sensor (100, 200, 300) with the gas sensor cap (214); a vent assembly (350) adapted to release at least a portion of the gas generated at the counter electrode out of the electrochemical gas sensor (100, 200, 300); wherein the vent assembly (350) includes the vent membrane (252) that is adapted to be heat sealed at a portion of the gas sensor cap (214) and wherein the plurality of solid features defines a cavity (406) between an internal surface of the plurality of pillar shaped moldings and a portion of the vent membrane (252).