Gas Sensor Dew Condensation Prevention via Thermal Conduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gas sensors in high temperature and high humidity environments face issues with dew condensation, leading to uneven temperature distribution and potential destruction of detection elements, which affects sensitivity.
Innovation Solution
A gas sensor design featuring a detection element supported by a protruding metal supporting member and a substrate with a heating element, allowing direct heating of the supporting member and substrate, preventing dew condensation from reaching the detection element, even when electrical power is stopped, and incorporating a PTC thermistor and surface/back face heaters to maintain the examination gas temperature above the dew point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the detection element is heated only by radiation heat from the heater unit or heater through the atmosphere, then the device complexity is reduced, but the heating amount becomes insufficient causing dew condensation to form on the detection element
Solution Approach 1:
A supporting member is introduced as an intermediary component between the heater unit and the detection element. This supporting member directly conducts heat from the heater unit to the detection element, serving as a thermal bridge that ensures sufficient heating while maintaining structural support functionality.
Solution Approach 2:
The heating function is segmented into two paths: radiation heat through the atmosphere for general heating, and direct conduction through the supporting member for targeted heating of the detection element. This segmentation ensures that the detection element receives adequate heat without requiring the entire system to be overly complex.
2Object-affected harmful factors
If electrical power is supplied to the detection element to prevent dew condensation, then the temperature distribution becomes locally uneven, but dew condensation is prevented
Solution Approach 1:
The supporting member acts as a thermal mediator that distributes heat evenly from the heater unit to the detection element. This indirect heating path prevents local temperature concentration that would occur with direct electrical power supply to the detection element, while still effectively preventing dew condensation.
Solution Approach 2:
The patent replaces the electrical heating method (direct power supply to detection element) with a thermal conduction method (heating through the supporting member). This substitution eliminates the temperature distribution problem while achieving the same dew condensation prevention goal.
3Loss of energy
If the supporting member is made of metal for direct heating, then the heat conduction efficiency is improved, but the risk of dew condensation on the supporting member itself increases
Solution Approach 1:
The supporting member is designed with non-uniform properties: the portion in contact with the heater unit has high thermal conductivity for efficient heat reception, while the portion supporting the detection element has lower thermal conductivity or is thermally insulated to prevent dew condensation. This local quality differentiation optimizes both heat conduction and dew condensation prevention.
Solution Approach 2:
The thermal conductivity parameter of the supporting member is varied along its length or at different zones. By changing this parameter locally, the system achieves efficient heat transfer where needed while preventing heat loss to areas where dew condensation would occur.
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
Prevents dew condensation on the detection element and supporting structures, maintaining sensitivity and durability by ensuring consistent heating and preventing dew condensation from forming within the gas sensor.
Implementation Method 1
the supporting member that supports the detection element is fixed so as to protrude from the heating element provided on the substrate; therefore, it is possible to directly heat the supporting member and the substrate connected to the detection element
Implementation Method 2
the heating element having a communication hole or the porous heating element; therefore, it is possible to prevent the temperature of the examination gas introduced into a gas detection chamber from decreasing to equal to or less than the dew point temperature
Implementation Method 3
a detection element that measures a gas concentration of a detection target gas contained in an examination gas
Data Source
AI summary
This gas sensor is provided with: a detection element that measures a gas concentration of a detection target gas contained in an examination gas; a substrate having a heating element; and a supporting member that is fixed to the substrate, protrudes from the heating element, and supports the detection element.