Laser triangulation for liquid film thickness measurements through multiple interfaces

Area of Science:

• Fluid dynamics
• Optical metrology
• Materials science

Background:

• Accurate measurement of liquid film thickness is essential for understanding interfacial phenomena.
• Gas-liquid contactors rely on stable liquid films for efficient operation.
• Existing measurement techniques may face challenges with multi-interface systems.

Purpose of the Study:

• To develop and validate a non-invasive optical technique for measuring liquid film thickness.
• To assess the stability of liquid films in a specific experimental setup.
• To provide a reliable method for evaluating liquid films in gas-liquid contactor applications.

Main Methods:

• Utilizing laser triangulation to measure distances to the film's bounding surfaces.
• Developing a refraction model to correct for optical path deviations through the liquid and window.
• Employing an empirical method for verification and comparison with the analytical approach.

Main Results:

• The laser triangulation method successfully measured local liquid film thickness.
• The developed refraction model improved the accuracy of thickness measurements.
• The analytical and empirical methods showed good agreement, validating the technique.

Conclusions:

• Laser triangulation offers a viable method for measuring liquid film thickness in complex systems.
• The technique is suitable for assessing the stability of liquid films relevant to gas-liquid contactors.
• Accurate film thickness measurement is key to optimizing gas-liquid contactor performance.