Measurement of aerosol-particle trajectories using a structured laser beam

Area of Science:

• Optical physics
• Particle dynamics
• Aerosol science

Background:

• Accurate measurement of micrometer-sized particle trajectories is crucial for understanding aerosol behavior and optimizing particle-sizing systems.
• Existing methods may face limitations in spatial resolution and accuracy within complex flow fields.
• Developing novel techniques is essential for advancing aerosol characterization.

Purpose of the Study:

• To introduce a new concept for measuring micrometer-sized particle trajectories in an inlet air stream.
• To present the design of a structured laser beam for particle trajectory measurement.
• To demonstrate the accuracy of the technique and its application in correcting particle-sizing systems.

Main Methods:

• A structured laser beam is generated using a light source and a mask to create a defined illumination volume.
• Particles traversing this volume scatter light, generating a time-resolved signal detected by a photodetector.
• The detected scattering waveform is decoded to reconstruct the particle's trajectory.

Main Results:

• The design for the structured laser beam is presented.
• The accuracy of the technique in determining particle position was demonstrated.
• The structured laser beam was shown to effectively measure and correct for the instrument-response function in optical-scattering particle-sizing systems.

Conclusions:

• A new concept for measuring micrometer-sized particle trajectories has been successfully introduced.
• The developed technique offers accurate particle position determination.
• This method has the potential to improve the performance of optical-scattering-based aerosol particle-sizing systems.