Porous Gas Sensor Lead Oxygen Flow Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The stability of gas sensor elements is compromised due to blocked oxygen flow paths near the reference electrode lead, leading to unstable oxygen concentration maintenance and sensor characteristics.
Innovation Solution
A gas sensor element design incorporating a measurement chamber, a pumping cell with oxygen ion-conductive solid electrolytes, and a plate-shaped oxygen concentration detection cell with permeable leads to prevent oxygen discharge reduction, ensuring stable oxygen concentration by allowing oxygen to flow through a through hole and be discharged externally.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the reference electrode lead is connected through a through hole in the plate-shaped cell member, then oxygen can be discharged from the reference electrode, but the flow path may become blocked in the vicinity of the through hole, reducing oxygen discharge and destabilizing sensor characteristics
Solution Approach 1:
The patent applies porous materials by forming the first lead portion with a porous structure that has oxygen permeability. This porous structure prevents blockage of the oxygen flow path while maintaining the lead's electrical and structural functions. The porous nature allows oxygen to pass through freely, eliminating the harmful blockage effect that would otherwise occur in the vicinity of the through hole.
Solution Approach 2:
The patent extends the first lead portion not only through the through hole but also along the inner circumferential wall of the through hole and onto the upper surface of the plate-shaped cell member. This multi-dimensional extension creates alternative pathways for oxygen flow, ensuring that even if one path is blocked, oxygen can still reach the exterior through other routes, thus maintaining stable oxygen discharge.
2Quantity of substance
If oxygen flow path is blocked near the through hole, then oxygen discharge through the through hole decreases, but this makes it difficult to maintain constant oxygen concentration in the reference electrode
Solution Approach 1:
The first lead portion is formed as a porous structure with oxygen permeability, enabling continuous oxygen transport from the reference electrode through the lead portion to the exterior. This porous structure ensures that oxygen can flow freely without blockage, maintaining both adequate oxygen discharge quantity and stable oxygen concentration in the reference electrode.
Solution Approach 2:
The extended configuration of the first lead portion, which covers the inner circumferential wall and extends to the upper surface, creates continuous oxygen flow paths. This ensures uninterrupted oxygen discharge from the reference electrode, maintaining both the quantity of oxygen discharged and the stability of oxygen concentration within the reference electrode.
3Reliability
If the first lead portion is formed to extend along the inner circumferential wall and cover the upper surface around the through hole, then oxygen flow is maintained, but the device complexity increases
Solution Approach 1:
The first lead portion serves multiple functions simultaneously: it provides electrical connection for the reference electrode, acts as an oxygen transport pathway through its porous structure, and extends along the inner circumferential wall to prevent blockage. This multi-functionality achieves reliable oxygen flow stability without requiring separate components for each function, thereby limiting the increase in device complexity.
Solution Approach 2:
The patent merges the electrical lead function with the oxygen transport function into a single integrated first lead portion structure. By combining these functions and extending the lead along the inner circumferential wall, the design achieves reliable oxygen flow without adding separate protective structures, thus balancing reliability improvement with controlled device 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
This design stabilizes the gas sensor element by maintaining consistent oxygen concentration, preventing fluctuations and enhancing overall sensor performance.
Implementation Method 1
The pumping cell includes a first solid electrolyte body having oxygen ion conductivity and a pair of pumping electrodes formed on the first solid electrolyte body. The pumping cell pumps oxygen into or out of the gas under measurement that has been introduced into the measurement chamber when a pumping current flows between the pair of pumping electrodes.
Implementation Method 2
The oxygen concentration detection cell includes a plate-shaped cell member formed into a plate shape and including at least a second solid electrolyte body having oxygen ion conductivity, a detection electrode, and a reference electrode having oxygen permeability.
Implementation Method 3
a reference electrode having oxygen permeability. The detection electrode is exposed to the measurement chamber, and the oxygen concentration detection cell generates an electromotive force corresponding to a difference in oxygen concentration between the detection electrode and the reference electrode.
Data Source
AI summary
A gas sensor element including a lead portion (79a) formed on a lower surface of an insulating member (76) and extending through a through hole (176) to an upper surface thereof, and a lead portion (79b) extending from the upper surface of the insulating member (76) through the through hole (176) to the lower surface of the insulating member (76) so as to cover the lead portion (79a) along the inner circumferential wall and a portion of the lower surface around the through hole. The lead portion (79a) has a section exposed to a space (230) on the lower surface side of the insulating member (76). The lead portion (79b) is disposed so as to face the insulating member (76) with the space (230) therebetween. The lead portion (79a) communicates with the outside through the space (230). Also disclosed is a method for producing the gas sensor element.