Optimizing Design Parameters for Miniaturized Condensation Particle Counters: Insights into Ultrafine Particle Detection
MOLLY J. HAUGEN, Shaamrit Balendra, Ashkay Kale, Lee Weller, Adam M Boies, University of Cambridge
Abstract Number: 394
Working Group: Instrumentation and Methods
Abstract
Urban particulates originate from diverse source, with near-source particles typically measuring less than 0.1 μm (here noted as ultrafine particles). These ultrafine particles pose significant challenges due to their ability to penetrate deep into the lungs, thus raising concerns for human health and overall air quality. Effective monitoring of these aerosols, both indoors and outdoors, is crucial for informed policy-making and monitoring air quality improvements. However, typical air quality sensors that focus on PM (PM2.5 and PM10), are primarily optical particle counters (OPCs). These types of sensors face limitations in detecting ultrafine particles, given their lower detection threshold of approximately 0.3 μm.
This study delves into the fundamental principles governing the lower size limits of a water-based condensation particle counter (CPC), drawing inspiration from prior research on the phenomena within the condensation particle counter growth chamber (CPC-GC).
The work reveals essential relationships critical for optimizing CPC-GC design including supersaturation, heat transfer, penetration, and droplet growth. These relationships, depicted within a design space framework, must also consider residence time and tube radius, both of which are crucial for achieving optimal droplet sizes and operational parameters.
By leveraging these insights, future iterations of CPC-GC designs can be miniaturized to operate within the optimized range delineated in the design space. This advancement holds promise for next-generation high-performance miniaturized CPC-GC designs and the development of portable CPC sensor systems, poised to revolutionize air quality monitoring.