TDLAS Gas Analysis in Sealed Containers via Inspection Chamber Vacuum
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Solution Overview
Problem
Existing methods for analyzing gaseous components in hermetically sealed containers, such as pharmaceutical vials, using Tunable Diode Laser Absorption Spectroscopy (TDLAS) are unreliable due to insufficient purging, which allows external gases to interfere with measurements, leading to uncertain results.
Innovation Solution
A method involving an apparatus that uses a controlled depressurization and gas flow within an inspection chamber to create a vacuum, ensuring a gas-free environment for the laser beam path, and employing TDLAS to accurately measure the concentration of gases like oxygen and water vapor within the container, thereby enhancing the reliability of leak detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If purging with dry air or nitrogen is used to cleanse the environment around the container, then external gas interference is reduced, but the purging is sometimes insufficient leading to unreliable measurement results
Solution Approach 1:
The patent creates a vacuum environment (inert atmosphere) in the inspection chamber surrounding the container during measurement. This vacuum prevents external gases from interfering with the laser beam path and eliminates the need for purging operations, directly resolving the contradiction between reducing gas interference and ensuring measurement reliability
Solution Approach 2:
The patent extracts external gases from the inspection chamber by creating a vacuum. This removes the harmful external gas environment entirely, allowing the laser beam to pass through without interference and ensuring reliable measurement results
2Reliability
If a vacuum is created in the inspection chamber to eliminate external gases, then measurement reliability is improved, but additional equipment and process complexity are required
Solution Approach 1:
The vacuum is created in advance before the measurement takes place. The inspection chamber is evacuated of external gases, and then the measurement is performed in this pre-prepared vacuum environment, ensuring reliability without requiring complex real-time adjustments during measurement
3Measurement precision
If the container is placed in a flow of purge gas, then the environment around the container is cleansed, but the laser beam path may still contain external gases affecting measurement accuracy
Solution Approach 1:
Instead of using flowing purge gas, the patent employs a static vacuum environment in the inspection chamber. This inert vacuum atmosphere ensures that no external gases are present in the laser beam path, achieving both high measurement precision and complete elimination of harmful external gases
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 ensures accurate and reliable detection of gaseous components in sealed containers by minimizing external gas interference, providing consistent and trustworthy results for assessing airtightness and detecting leaks.
Implementation Method 1
A widely used technique for checking vials and bottles for leaks comprises analysing the gaseous component in their headspace by absorption spectroscopy. This technique, known as Tunable Diode Laser Absorption Spectroscopy (TDLAS)... is based on the consideration that a gas contained in a vial or bottle, when crossed by radiation of suitable wavelength, absorbs the radiation to a greater or lesser extent according to its quantity. The concentration of the gas being analysed can be calculated by analysing the absorption spectrum of the radiation and on the basis of Beer's law.
Implementation Method 2
a method for analysing a gaseous component present in a hermetically sealed container... comprises the steps of: placing the container in an inspection chamber; creating a vacuum in the inspection chamber
Data Source
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AI summary
In a method for analysing a gaseous component present in a hermetically sealed container (2), the latter is placed in a measuring station (S) between a laser beam emitter (20) and a receiver (21), the laser beam being emitted towards the receiver (21) and through the portion of the container (2) where the gaseous component is located, and the concentration of the gaseous component is inferred by analysing the spectrum of the laser beam absorbed by the gaseous component; the step of emitting the laser beam is preceded by a step of closing the container (2) in an inspection chamber (10) where the laser beam itself is subsequently confined, and a step of depressurizing the inspection chamber (10).