Monolithic Multi-Laser Gas Analyzer for Stable Mobile Alignment

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Solution Overview

Problem

Existing gas analyzers using laser absorption spectroscopy are bulky, expensive, and complex, limiting their use in mobile applications and requiring skilled operation, while current multipass cells suffer from gas adsorption issues and alignment difficulties.

Innovation Solution

A compact, user-friendly gas analyzer with multiple lasers housed in a monolithic laser housing, combined with a glass multipass cell and adjustable mirror holder, utilizing a startup algorithm for precise spectral alignment and reduced gas interaction with metal surfaces, and employing inert gas filling to prevent condensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple lasers are used for multi-gas measurement, then measurement capability is improved, but device complexity increases

Engineering Contradiction:
Improvemulti-gas measurement capabilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Multiple lasers are integrated into a single common housing with shared optical components, including a common beam path, shared photodetector, and common electronic control system. This merging approach enables multi-gas measurement capability while reducing overall system complexity compared to using separate analyzers for each gas.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The analyzer is designed with universal components that can detect multiple gas species. The photodetector, optical path, and processing electronics serve multiple functions by detecting absorption signals from different lasers targeting different gases, making the system adaptable to various measurement needs.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Length of stationary object

If traditional multipass cell is used, then optical path length is increased, but gas adsorption and alignment difficulty increase

Engineering Contradiction:
Improveoptical path lengthVSAvoidalignment ease
Core Design Contradiction:
Length of stationary objectVSEase of operation

Solution Approach 1:

The mirrors in the multipass cell are coated with dielectric layers having specific reflectivity characteristics optimized for the laser wavelengths used. These wavelength-specific optical coatings ensure high reflectivity for the particular laser frequencies while minimizing gas adsorption effects, achieving long optical path length with improved alignment stability.

Inventive Principle:
Principle #32Color changes

3Volume of moving object

If laser housing is made compact, then mobility is improved, but shock and vibration resistance decreases

Engineering Contradiction:
Improvehousing volumeVSAvoidshock and vibration resistance
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The laser housing employs composite construction combining rigid materials for structural integrity with vibration-damping materials for shock resistance. This composite approach maintains a compact volume while providing sufficient protection against shock and vibration during mobile operations.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The housing design incorporates vibration isolation elements and shock-absorbing features that are pre-installed to protect sensitive optical components before shock or vibration events occur. This beforehand cushioning enables compact design while maintaining reliability under mobile conditions.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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

The solution provides a cost-effective, accurate, and reliable gas analysis capable of simultaneous multi-gas measurement, with improved robustness against shock and vibration, and simplified assembly and alignment, enabling mobile applications.

Implementation Method 1

the concentration (i.e. the volume mixing ratio) of each gas is determined by application of Beer-Lambert's law. When light of a mid-infrared laser source is sent through a gas sample containing an absorbing gas species, its absorption can be detected, if the frequency of the light source corresponds to the frequency of a ro-vibrational transition.

Methodology Applied
Scientific EffectBeer-Lambert's law: Absorption (EM radiation)

Implementation Method 2

a multi-pass cell with reduced pressure, the laser light being reflected between two mirrors to create a long interaction path of the light with the sampled gas

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

a photodetector, more precisely an infrared (IR) detector, corresponding to the light source's wavelength (e.g. MCT)

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP4217710B1Gas analyser apparatus
Publication Date: 2025.12.10 MIRO ANALYTICAL AG
  • EP4217710B1 patent drawingFigure 1
  • EP4217710B1 patent drawingFigure 2
  • EP4217710B1 patent drawingFigure 3~4

AI summary

A gas analyser apparatus using laser absorption spectroscopy comprises at least two lasers (66), preferably up to five, six or seven lasers (66), and a laser housing (6). The at least two lasers (66) are mounted in the laser housing (6). The laser housing (6) comprises a monolithic main body (61) defining an interior space for receiving the lasers (66) and a lid (60) for sealingly closing the main body (61). The laser housing (6) is arranged within an outer housing (1) of the gas analyser apparatus. This gas analyser can be assembled and adjusted in a quite simple way.