# A PULSED CONDENSATION PARTICLE COUNTER FOR COST EFFECTIVE MONITORING OF ULTRAFINE AIRBORNE PARTICLES

> **NIH NIH R44** · AEROSOL DYNAMICS, INC. · 2023 · $612,102

## Abstract

A PULSED CONDENSATION PARTICLE COUNTER FOR
COST EFFECTIVE MONITORING OF ULTRAFINE AIRBORNE PARTICLES
ABSTRACT
This project will develop and validate a new approach for affordably monitoring the number concentration of
ultrafine airborne particles. Ultrafine particles are specifically implicated in health, and yet are not detected by
lower-cost sensors. Our approach is a Pulsed Condensation Particle Counter that uses adiabatic expansion
combined with single particle counting. Our Phase I results demonstrate that this approach is reliable over
months of continuous operation, with ±10% agreement with expensive, research-grade condensation particle
counters. Our target is an affordable portable instrument, priced at a fraction of the cost of current instruments,
that measures the particle number concentration with known accuracy and precision. The envisioned
commercial instrument will include a commercial optical counter and report ultrafine particle number
concentration and estimated PM2.5 mass.
This Phase II project will improve the performance of the Phase I system, refine the supporting components,
and integrate the electronics and components into a compact system. The complete prototype system will be
tested under both laboratory and field conditions. Instrument precision and accuracy over a range of particle
sizes and concentrations will be evaluated with monodispersed, laboratory aerosols, using particle sizes
ranging from 5 nm to 2500 nm, and concentrations from near zero to several hundred thousand per cubic
centimeter. Instrument robustness will be evaluated through stress-testing at extremes in temperature (5°-
40°C) and humidity (5%-95%). Monitoring performance and stability will be tested through comparison with
collocated benchtop instruments over weeks of unattended operation. Measurements under field conditions
will be conducted in collaboration with a local university exposure study. Validation as a monitor will be done in
collaboration with an air monitoring district. The objective is a compact, cost-effective monitor with a particle
detection limit below 5 nm, with precision of ±10% for concentrations between 10 - 104/cm3, and precision of at
least ±15% for concentrations reaching 105/cm3, and data recovery of at least 90%.

## Key facts

- **NIH application ID:** 10599312
- **Project number:** 5R44ES031458-03
- **Recipient organization:** AEROSOL DYNAMICS, INC.
- **Principal Investigator:** Susanne Vera Hering
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $612,102
- **Award type:** 5
- **Project period:** 2020-04-01 → 2026-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10599312

## Citation

> US National Institutes of Health, RePORTER application 10599312, A PULSED CONDENSATION PARTICLE COUNTER FOR COST EFFECTIVE MONITORING OF ULTRAFINE AIRBORNE PARTICLES (5R44ES031458-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10599312. Licensed CC0.

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