Within the instrument, particles pass through successive low-pressure impactor stages. At these stages, electrical charging and aerodynamic separation work together, so particles are directed according to aerodynamic diameter before reaching collection plates. This staged arrangement lets the ELPI distinguish particle populations across its measurement range while retaining a rapid electrical readout rather than relying on slow post-collection analysis.
Each collection plate receives particles separated at its corresponding stage and remains electrically isolated from the others. That separation allows the electrical signal from one stage to be measured independently. Comparing signals across the stages provides the basis for determining how particle concentration is distributed by aerodynamic diameter, while keeping stage-specific information available for interpretation.
The current measured at each stage serves as a rapid signal for the amount of particle material collected there. Reading all stages together produces a particle size distribution and concentration profile across the instrument's range. Because the signal is electrical and obtained during collection, researchers can follow particle populations in real time without laborious post-collection analysis.
To make a measurement, the instrument draws in an airborne sample and sends it through the low-pressure impactor stages. Particles become electrically charged, are separated by aerodynamic diameter, and are collected on the corresponding isolated plates. The instrument then measures current at each stage to generate a real-time size and concentration distribution.
In biology, ELPI data can characterize bioaerosols, aerosolized cells, and microorganisms by showing how their airborne particle populations are distributed across aerodynamic diameters. That information helps connect particle size patterns with transport through air and deposition behavior. It also gives researchers a rapid way to examine biologically relevant aerosols without depending solely on laborious analysis after collection.
During inhalation-exposure studies, the instrument can track the particle characteristics present in an airborne exposure rather than providing only a post-collection snapshot. Researchers can also apply it to particle-generating processes to observe the resulting size and concentration profile. These measurements support assessment of how biological aerosols move, deposit, and may contribute to potential health risks.