Gas Sensor Chamber Segmentation for Accurate H2O and CO2 Measurement
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Solution Overview
Problem
Existing gas sensors face reduced measurement accuracy due to re-reduction of water vapor and carbon dioxide, which leads to superimposed currents affecting concentration measurements.
Innovation Solution
A multi-gas sensor with a sensor element comprising oxygen-ion conductive solid electrolyte chambers and pump cells that perform controlled oxygen pumping and oxidation to isolate and measure water vapor and carbon dioxide concentrations accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a three-chamber gas sensor configuration is used to measure water vapor and carbon dioxide concentrations, then the sensor can perform multi-gas measurement, but measurement accuracy deteriorates due to re-reduction of H2O and CO2 in the first internal space
Solution Approach 1:
The sensor divides the measurement space into multiple chambers (first internal space for reduction, second internal space for H2 measurement, third internal space for CO measurement) with diffusion control parts between them. This segmentation allows separate handling of different gas components and prevents re-reduction of H2O and CO2 by spatial isolation, resolving the contradiction between multi-gas measurement capability and measurement accuracy.
Solution Approach 2:
Diffusion control parts are introduced as intermediary elements between the first internal space and the second/third internal spaces. These intermediaries control the diffusion of gases, preventing H2O and CO2 from flowing back to the first internal space where they would be re-reduced, thereby maintaining measurement accuracy while preserving multi-gas measurement functionality.
2Difficulty of detecting and measuring
If H2O and CO2 are reduced to H2 and CO in the first internal space, then the sensor can detect gas components, but re-oxidation of H2 and CO generates superimposed currents that reduce measurement accuracy
Solution Approach 1:
The sensor separates the detection of H2O and CO2 from the detection of H2 and CO by placing them in different chambers (second and third internal spaces) with physical barriers. This segmentation ensures that H2 and CO generated in the first chamber cannot return to cause re-oxidation and superimposed currents, while still allowing detection of all four gas components through their respective chambers.
Solution Approach 2:
The invention extracts H2O and CO2 from the measurement path before they can undergo re-reduction and re-oxidation cycles. By measuring these gases in separate chambers isolated from the reduction zone, the harmful re-oxidation process is eliminated, removing the source of measurement error while preserving the ability to detect all gas components.
3Duration of action of stationary object
If measurement is continued over time, then the sensor provides continuous monitoring, but H2O and CO2 flow back to the first internal space and are re-reduced, reducing measurement accuracy
Solution Approach 1:
The diffusion control parts are pre-configured to prevent backflow of H2O and CO2 to the first internal space before re-reduction can occur. This preliminary preventive action ensures that even during continuous operation, the gases cannot return to the reduction zone, maintaining measurement accuracy indefinitely without requiring periodic resetting or maintenance.
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 suppresses the reduction in measurement accuracy by isolating and measuring water vapor and carbon dioxide concentrations, ensuring precise concentration determination.
Implementation Method 1
an oxygen pumping-out means capable of performing first pumping-out operation to pump out oxygen contained in the measurement gas so that substantially all water vapor and carbon dioxide contained in the measurement gas are reduced
Implementation Method 2
the first measurement pump cell is capable of pumping oxygen into the first measurement chamber to selectively oxidize, in the first measurement chamber, hydrogen generated by reduction of water vapor
Implementation Method 3
the second measurement pump cell is capable of pumping oxygen into the second measurement chamber to oxidize, in the second measurement chamber, carbon monoxide generated by reduction of carbon dioxide
Implementation Method 4
a sensor element having a structure formed of an oxygen-ion conductive solid electrolyte
Data Source
AI summary
An adjustment pump cell performs first pumping-out operation to pump out oxygen so that all H2O and CO2 in a measurement gas introduced into a first chamber are reduced, a first measurement pump cell selectively oxidizes H2 in a second chamber, a second measurement pump cell oxidizes CO in a third chamber, a concentration of H2O and CO2 are identified based on currents generated in respective oxidization, the adjustment pump cell can further perform second pumping-out operation to pump out oxygen from the first chamber to the extent that H2O and CO2 are not reduced in the middle of the first pumping-out operation, and reduction of H2O and CO2 in the first chamber is interrupted upon start of the second pumping-out operation, so that H2O and CO2 generated in the second chamber or the third chamber are emitted outside an element.