Compact Infrared Gas Measuring Cell With Multi-Reflection Cavity

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Solution Overview

Problem

Existing measuring cells for spectral analysis of gas samples face challenges in reducing their outer volume while maintaining a long measuring distance, with limited reflection surfaces and complex ray path configurations, which complicates the integration with electronic components and affects the reliability of spectroanalytical evaluations.

Innovation Solution

The design incorporates a measuring cell with a plurality of reflections from carefully positioned and shaped reflection surfaces, including concave and plane surfaces, to create a long measuring distance within a compact volume, allowing for efficient light beam propagation and integration with electronic components, and is adapted to fit within specific dimensions and focal points for infrared light analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the outer volume of the measuring cell is reduced, then the compactness is improved, but the measuring distance becomes shorter

Engineering Contradiction:
Improveouter volume of measuring cellVSAvoidmeasuring distance
Core Design Contradiction:
Volume of moving objectVSLength of stationary object

Solution Approach 1:

The patent transforms the light propagation from a straight linear path to a multi-dimensional reflected path using multiple reflection surfaces (first reflection surface, second reflection surface, third reflection surface). This allows the light beam to traverse a longer effective measuring distance while the physical dimensions of the measuring cell remain compact, effectively utilizing three-dimensional space for optical path extension.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent implements a nested arrangement where multiple reflection surfaces are positioned within the compact cavity structure. The first, second, and third reflection surfaces are arranged in a nested configuration that maximizes the optical path length within the limited physical volume, allowing the light beam to reflect sequentially between these surfaces and achieve an extended measuring distance.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Length of stationary object

If multiple reflection surfaces are added to extend measuring distance, then the measuring distance is improved, but the device complexity increases

Engineering Contradiction:
Improvemeasuring distanceVSAvoidcomplexity of reflection surfaces configuration
Core Design Contradiction:
Length of stationary objectVSDevice complexity

Solution Approach 1:

The patent employs curved reflection surfaces, specifically a second reflection surface with a predetermined curvature radius, to focus and redirect light beams efficiently. This curvature enables the light to bounce between surfaces in a controlled manner, extending the optical path without requiring complex angular arrangements or multiple discrete reflective elements, thereby reducing overall device complexity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Volume of moving object

If the cavity is made thin to reduce volume, then the volume is improved, but the light beam passage and reflection paths are restricted

Engineering Contradiction:
Improvecavity volumeVSAvoidlight beam passage capability
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The patent compensates for the thin cavity limitation by introducing multiple reflection surfaces arranged at different positions and orientations. The light beam propagates through the thin cavity by reflecting between these surfaces, effectively creating a longer optical path within the constrained physical thickness. This multi-dimensional reflection approach overcomes the geometric constraints of a thin cavity design.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 enables a compact measuring cell with a selected ratio of measuring distance to volume, allowing for reliable spectroanalytical evaluations with improved integration of electronic components and efficient light beam management, enhancing the accuracy and efficiency of gas sample analysis.

Implementation Method 1

a utilization of a plurality of reflections of the emitted light beam(s) from and between a number of reflection surfaces and/or simplified reflection points assigned to the inner cavity of the measuring cell

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2494333B1A measuring cell adapted to spectral analysis
Publication Date: 2016.04.13 SENSEAIR
  • EP2494333B1 patent drawingFigure 1~3
  • EP2494333B1 patent drawingFigure 4~6
  • EP2494333B1 patent drawingFigure 7~8

AI summary

The present invention embraces a measuring cell (1) adapted for a spectral analysis of a gas sample, where this measuring cell is designed and adapted to co-ordinate, from a means (4) generating IR light, emitted converging and/or diverging light beams in a direction toward a means (5) receiving IR light, by a plurality of reflections of emitted light beams from a number of reflection surfaces (M1-M6) assigned to the inner cavity of the measuring cell, thereby allowing creating a predetermined measuring distance ("L") in the inner cavity (1c) of the measuring cell (1), from the means (4) generating IR light to the means (5) receiving IR light. The cavity (1c) of said measuring cell is adapted to contain the gas sample ("G") intended for a spectroanalytical absorption measurement, besides which light beams from the means (4) generating IR light are, via a reflection surface (M7), convergingly directed to and/or adapted, such as reflectable, in a first reflection surface (M1) in order to, when reflected, via a first focal point ("F1"), as diverging light beams become directed to a second reflection surface, shaped as a concave reflection surface (M2), as well as via third (M3) and fourth (M4, M5 and M6) reflection surfaces become converging to a focal point ("F3"), in or in the vicinity of the means (5) receiving light, in order to form a compact measuring cell (1).