Gas Sensor Inlet Design for Diffusion Resistance
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Solution Overview
Problem
Gas sensor devices face a trade-off between responsiveness and measurement accuracy due to increased diffusion distance and diffusion resistance in diffusion rate controlling paths, leading to decreased measurement accuracy when attempting to improve responsiveness.
Innovation Solution
A gas sensor device with a specific design where the gas inlet and inner void space are structured to provide controlled diffusion resistance, with a relation of 1000≤(L1/S1)×(L2/S2)≤5000, ensuring compatibility between responsiveness and measurement accuracy, where L1/S1 and L2/S2 represent diffusion resistance indicators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If diffusion rate controlling paths are introduced to control oxygen concentration, then measurement accuracy is improved, but diffusion distance increases leading to decreased responsiveness
Solution Approach 1:
The gas inlet is designed with a porous structure that provides controlled diffusion resistance. The porous material allows gas molecules to diffuse through while maintaining a specific resistance level, enabling the system to control oxygen concentration in the inner void space without requiring long diffusion paths. This resolves the contradiction by providing the necessary diffusion control through material properties rather than geometric length, thus maintaining responsiveness while achieving measurement accuracy.
Solution Approach 2:
The invention changes the diffusion resistance parameter by controlling the structural parameters of the gas inlet (dimensions L1, S1) and the inner void space (distance L2, sectional area S2). By optimizing the relationship 1000≤(L1/S1)×(L2/S2)≤5000, the system achieves the right balance between diffusion control for accuracy and diffusion speed for responsiveness, resolving the technical contradiction through parameter optimization.
2Speed
If diffusion resistance in the first diffusion rate controlling path is decreased to improve responsiveness, then measurement gas flows more freely, but oxygen concentration control in the measurement gas deteriorates
Solution Approach 1:
The gas inlet acts as an intermediary element between the external environment and the inner void space. It provides the necessary diffusion resistance to control oxygen concentration while allowing measurement gas to flow through. By positioning this intermediary at the entrance, the system achieves oxygen concentration control without requiring long diffusion paths through the entire sensor structure, thus maintaining responsiveness.
3Speed
If diffusion resistance in the second diffusion rate controlling path is decreased to improve responsiveness, then gas flows faster to the sensor cell, but oxygen concentration control in the first inner void deteriorates
Solution Approach 1:
The gas inlet is designed to provide preliminary diffusion resistance action at the very entrance of the device. By controlling the diffusion resistance at this initial stage (through dimensions L1 and S1), the system pre-regulates the gas flow characteristics before the gas enters the inner void space. This preliminary action ensures that oxygen concentration is controlled early in the process, eliminating the need for additional diffusion resistance in subsequent paths and maintaining responsiveness throughout.
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 achieves a balance between responsiveness and measurement accuracy by adjusting the diffusion resistance indicators, improving measurement accuracy while maintaining adequate responsiveness.
Implementation Method 1
a gas inlet through which the measurement gas is introduced into the inner void space and which is shaped to provide a given diffusion resistance to the measurement gas introduced into the inner void space
Implementation Method 2
a sensor cell which is made up of a first portion of an oxygen ion conductive solid electrolyte body and a pair of sensor electrodes disposed on the solid electrolyte body
Data Source
AI summary
A gas sensor device is equipped with the sensor cell, the pump cell, the inner void space, and the gas inlet. The sensor cell is created by a portion of the solid electrolyte body and a pair of sensor electrodes disposed on the solid electrolyte body. The pump cell is created by a portion of the solid electrolyte body and a pair of pump electrodes disposed on the solid electrolyte body. The inner void space faces the sensor electrode and the pump electrode. If a dimension of said gas inlet in a direction in which the measurement gas flows in the gas inlet is defined as L1, a sectional area of the gas inlet taken perpendicular to the direction of flow of the measurement gas in the gas inlet is defined as S1, a distance between the gas inlet and the sensor cell is defined as L2, and a sectional area of the inner void space taken perpendicular to a direction in which the pump cell and the sensor cell are aligned with each other is defined as S2, a relation of 1000≤(L1/S1)×(L2/S2)≤5000 is met.