Laser Spectroscopy for Non-Destructive Gas Analysis in Sealed Packaging
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Solution Overview
Problem
Current non-destructive testing methods for sealed food packagings are inadequate as they either destroy the packaging during sampling, provide complex and expensive systems, or cannot measure gas concentrations accurately without additional channels, limiting their applicability to liquids and not suitable for solids.
Innovation Solution
An apparatus using laser spectroscopy with a collimated laser beam and photo-detector system that measures gas concentration by analyzing absorption signals through optically transparent packaging, employing a triangulation system for precise distance measurement and a containment chamber to minimize interference, allowing for absolute gas concentration measurement without altering the packaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If gas sampling using a syringe is performed to measure gas concentration inside sealed packaging, then reliable measurement results are obtained, but the packaging is destroyed and cannot be re-introduced into production
Solution Approach 1:
The patent replaces the mechanical syringe sampling system with an optical measurement system. A laser beam is transmitted through the packaging wall to measure gas concentration non-contactingly, eliminating the need to open or pierce the packaging. This substitution of mechanical intrusion with optical non-contact measurement resolves the contradiction between obtaining reliable measurements and preserving packaging integrity.
Solution Approach 2:
The patent introduces light as an intermediary medium to perform measurements. Instead of directly sampling gas through the packaging, the system uses laser light transmitted through the packaging wall to detect gas concentration via absorption spectroscopy. This intermediary approach allows measurement without direct contact or destruction of the packaging.
2Object-affected harmful factors
If laser spectroscopy is used to measure gas concentration non-destructively, then packaging integrity is maintained, but the system becomes complex and expensive
Solution Approach 1:
The patent employs a multi-functional optical detection system that can measure multiple gas parameters (oxygen concentration, water vapor content, carbon dioxide concentration) using a single integrated apparatus. The system uses one laser source and detection channel to perform multiple measurements, reducing overall system complexity compared to having separate systems for each gas parameter.
Solution Approach 2:
The system measures different gas concentrations by changing the wavelength parameters of the laser beam. By tuning the laser to different absorption wavelengths corresponding to different gases, the same optical path and detection system can sequentially measure multiple gas parameters, avoiding the need for multiple separate measurement channels.
3Measurement precision
If a second measurement channel for water vapor is added to provide reference for absolute gas measurement, then measurement accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent uses periodic modulation of the laser beam and synchronous detection to extract multiple gas concentration signals from a single measurement channel. By modulating the laser and using lock-in detection techniques, the system can sequentially and accurately measure different gas parameters without requiring separate physical channels, reducing system complexity while maintaining measurement accuracy.
Solution Approach 2:
The system performs preliminary calibration measurements and stores reference absorption spectra for different gases. During actual measurement, the system compares the measured absorption signals against these pre-stored references to determine gas concentrations. This preliminary preparation allows accurate absolute measurements without requiring complex real-time reference measurements.
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
Enables reliable, non-destructive, and absolute gas concentration measurement in various packaging types, including solids and liquids, suitable for in-line testing without damaging the packaging, providing accurate and efficient results.
Implementation Method 1
measuring, through laser spectroscopy, the radiation portion of the diffusive type which exits from a food packaging, after sending a laser radiation thereinto... the absorption of the radiation operated by a determined gas present in the packaging
Implementation Method 2
measuring the radiation portion of the diffusive type which exits from a food packaging, after sending a laser radiation thereinto... the absorption of the radiation operated by a determined gas
Data Source
AI summary
An apparatus for the non-destructive testing of the integrity and/or suitability of sealed packagings having at least one portion (111,121) at least partially optically transparent, preferably food packagings, in particular through a verification of conformity of the atmosphere inside such food packagings, wherein the apparatus comprises at least one inspection area (20); at least one laser source (11) with an optical axis (A); at least one detector (13) positioned so as to detect at least one portion of back-scattered beams (12′) following the collision of the laser beam (12) emitted by the laser source (11) with a target (100,200) and provide—at the output—a representative datum of an absorption spectrum of the gas. The apparatus includes means for measuring a distance covered by the laser beam (12) and electronic processing means for calculating the concentration of the gas.