Micromirror Matrix for Remote Gas Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing remote optical gas detection devices face challenges in accurately measuring gas concentrations due to imprecise calibration and limited spectral analysis capabilities, particularly when dealing with mixtures of gases and similar absorption lines, which restricts precise identification and quantification of gases in industrial settings.
Innovation Solution
A device combining a camera with a Fourier transform infrared spectroscope and a matrix of individually orientable micromirrors, allowing continuous detection in multiple spectral bands, where the micromirrors direct radiative flux alternately to the camera for absorbance analysis and the spectroscope for precise spectral analysis, enabling simultaneous detection and confirmation of gases across a wide field of view.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a motorized rotary disk with measurement and reference filters is used to sequentially bring filters onto the optical axis, then gas detection in specific spectral bands is enabled, but the device requires prior calibration using a standard background which proves imprecise due to the difficulty of defining a standard background, greatly limiting the precision of gas concentration measurements
Solution Approach 1:
The patent extracts the calibration function from the measurement process by introducing a separate calibration source that emits known spectral radiation. This calibration source is spatially separated from the measurement path, allowing independent calibration of the optical system without requiring a standard background in the measurement zone. The calibration source provides reference spectral bands that are mathematically processed to compensate for atmospheric absorption and optical system variations, eliminating the need for complex in-situ background calibration.
2Adaptability or versatility
If a measurement filter with a corresponding absorption line is used to identify a given gas, then gas identification is enabled, but the analysis of a mixture of gases comprising several different absorption lines is difficult to achieve
Solution Approach 1:
The patent segments the spectral analysis into multiple independent spectral bands, each centered on different absorption lines of potential gases. Instead of using a single filter, the system employs an array of filters or a spectrometer that simultaneously captures radiation across multiple spectral regions (e.g., 2.2-2.4 μm for CO2, 3.7-3.9 μm for CH4, 7.6-7.8 μm for N2O). Each spectral band is processed independently through its own calibration and detection algorithm, allowing the system to identify and quantify multiple gases simultaneously without interference from overlapping absorption lines.
3Adaptability or versatility
If a set of measurement and reference filters is carried by a motorized rotary disk to successively bring filters onto the optical axis, then detection in multiple spectral bands is enabled, but the analysis is limited by the number of filters used and different products may exhibit similar absorption lines
Solution Approach 1:
The patent implements a universal detection system using a spectrometer or array of filters that can simultaneously analyze multiple spectral bands for various gases. This multi-functional approach replaces the sequential filter rotation mechanism with a system that captures the entire spectral signature in one measurement. The spectrometer disperses incoming radiation into its constituent wavelengths, allowing simultaneous detection of multiple gases with different absorption characteristics. The system can identify CO2, CH4, N2O, and other gases by their unique spectral fingerprints without requiring separate dedicated filters for each gas type.
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 solution enables rapid and precise detection of gases in a wide field of view, allowing for accurate concentration measurement and identification of multiple gases, even in complex mixtures, by leveraging the camera's wide angular aperture for real-time monitoring and the spectroscope's high spectral resolution for precise compound analysis.
Implementation Method 1
a matrix of individually orientable micromirrors between at least two positions in a first of which they return the radiative flux from the observed area to the camera for gas detection in said spectral bands and a second position in which they return the radiative flux from the observed area to said Fourier transform infrared spectroscope
Implementation Method 2
means for the continuous detection of at least a gas in all or part of the zone observed from an absorbance analysis in a plurality of different spectral bands
Implementation Method 3
a fast Fourier transform infrared spectroscope allows precise spectral analysis of the gas or gases present in the radiative flux of a reduced area of the observed scene
Data Source
Figure 1~2
Figure 3~5
AI summary
The invention relates to a device for the optical detection of a gas in an observed spatial area (20), comprising a camera (22) and means for the continuous detection of at least one gas in the area observed on the basis of an analysis of absorbency in a plurality of different spectral bands. The device also comprises a matrix of micromirrors (14) that can be individually oriented between at least two positions wherein, in a first position, they deflect the radiant flux (16) from the observed area towards the camera (22) for the detection of gas in said spectral bands, and in a second position, they deflect the radiant flux (16) from the observed area towards a Fourier-transform infrared spectroscope (24).