Electrostatic Classifiers and DMAs

Electrostatic classifiers and DMAs provide the foundation for mobility-based aerosol sizing. By exposing charged particles to a controlled electric field within a laminar sheath flow, a DMA selectively transmits a narrow band of electrical mobility, which correlates with particle size. This approach supports robust measurements from a few nanometers through the submicron range and enables true monodisperse aerosol generation for downstream experiments.

Key advantages for research and development:

• High Resolution: Adjustable sheath-to-aerosol ratios and DMA geometries help refine transfer functions for sharper size cuts.
• Reproducibility: Stable flow control and integrated charge neutralization promote consistent classification across long studies.
• System Flexibility: Interchange DMA columns, neutralizers, and flow modules to align with evolving methods.
• Workflow Integration: Combine with condensation particle counters, Faraday cup electrometers, optical detectors, or spectrometers to form complete systems.

Typical applications:

• Instrument Calibration: Produce size-selected aerosols to validate CPCs, OPCs, SMPS, and other detectors.
• Materials Research: Generate reference nanoparticle sizes for synthesis, agglomeration studies, and functional testing.
• Filtration and Respiratory Studies: Characterize penetration versus particle size with precise upstream challenges.
• Atmospheric Science: Resolve ambient nanoparticle distributions and support source apportionment studies.

Selection guidance:

• DMA Geometry: Long-column DMAs favor resolution; compact designs support portability and higher throughput.
• Charge Neutralization: Choose soft X-ray or other neutralization options to achieve near-Boltzmann charge distributions.
• Flow Architecture: Higher sheath flows can improve resolution; verify compressor or clean air supply capacity.
• Compatibility: Confirm interfaces with CPCs, aerosol generators, and data systems for a seamless setup.

With modern controllers, automated scans, and data connectivity, electrostatic classifiers and DMAs help teams accelerate method development, reduce measurement uncertainty, and collaborate across sites. Whether you are building a primary sizing standard for your lab or creating a turnkey classification line for production support, these components provide a dependable backbone for nanoparticle research. Speak with our team to configure the right column, flows, and accessories for your protocols.