Gas Sensor Optical Geometry for Filter Elimination
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Solution Overview
Problem
Conventional optical gas sensors require high-quality, expensive optical filters to suppress the intense radiation source emission, which increases manufacturing complexity and costs, and often suffer from signal drift due to variations in source radiation intensity.
Innovation Solution
The design incorporates an optics assembly that converges the radiation source away from the luminescence detector, allowing for the use of simpler filters or eliminating them altogether, and includes a reference channel to compensate for source radiation intensity variations, enhancing sensor accuracy and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high-quality optical filter is used to suppress LED radiation, then the sensor efficiency is improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The patent extracts and removes the high-quality optical filter from the sensor system by using a non-linear optical scheme where the LED and detector are positioned on the same side of the gas-sensitive layer, eliminating the need for complex interference filters while maintaining sensor efficiency
Solution Approach 2:
The patent changes the linear optical arrangement to a non-linear configuration, positioning both the radiation source and detector on the same side of the gas-sensitive layer, which fundamentally alters the light path geometry to avoid direct LED radiation exposure at the detector
2Measurement precision
If a high-quality optical filter is used to suppress LED radiation, then the measurement accuracy is improved, but the manufacturing cost increases
Solution Approach 1:
The patent removes the expensive high-quality optical filter from the system by implementing a non-linear optical scheme that inherently protects the detector from direct LED radiation, thereby maintaining measurement accuracy while significantly reducing manufacturing cost
Solution Approach 2:
The patent replaces expensive, complex interference filters with a simpler, more economical optical configuration using basic optical components and geometry, achieving the same radiation suppression function at lower cost
3Productivity
If the radiation source intensity varies, then the sensor response changes, but the measurement stability deteriorates
Solution Approach 1:
The patent implements a feedback mechanism by introducing a reference channel that continuously monitors the LED radiation intensity and uses this information to compensate for variations in the measurement channel, thereby maintaining measurement stability despite source intensity fluctuations
Solution Approach 2:
The patent creates an asymmetric optical configuration where the measurement channel and reference channel have different optical paths, allowing the reference channel to specifically monitor source variations without being affected by gas concentration changes, enabling accurate compensation
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 approach reduces the need for high-quality filters, simplifies the manufacturing process, and improves the sensor's sensitivity and accuracy by minimizing source radiation interference and stabilizing the measurement signal.
Implementation Method 1
a photoluminescent material which, upon absorption of radiation of a first wavelength within the first waveband, emits radiation of a second wavelength, the photoluminescent material being responsive to the presence of a target gas species in the gas sample such that the intensity of the emitted radiation varies according to the concentration of the target gas species
Implementation Method 2
an optics assembly adapted to receive radiation emitted by the radiation source and to converge the radiation towards a second location at which the luminescence detector assembly cannot receive radiation
Data Source
AI summary
In one aspect of the disclosure, a gas sensor is provided, comprising: a chamber for containing a gas sample in use, and a radiation source adapted to emit radiation within a first waveband. A photoluminescent material, upon absorption of radiation of a first wavelength within the first waveband, emits radiation of a second wavelength, the photoluminescent material being responsive to the presence of a target gas species in the gas sample. The gas sensor further comprises a luminescence detector assembly. The luminescence detector assembly is adapted to detect radiation of the second wavelength and output a corresponding measurement signal related to the concentration of the target gas species. An optics assembly is adapted to receive radiation emitted by the radiation source and to converge the radiation towards a location at which the luminescence detector assembly cannot receive radiation.