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

脉冲凝聚粒子计数器 空气中超细颗粒物的成本效益监测 摘要 该项目将开发和验证一种新的方法，用于监测 空气中的超细微粒超细颗粒物特别涉及健康，但没有检测到 低成本传感器我们的方法是使用绝热膨胀的脉冲凝聚粒子计数器 结合单粒子计数。我们的第一阶段结果表明，这种方法是可靠的， 连续运行数月，与昂贵的研究级冷凝颗粒的一致性为±10% 柜台我们的目标是一个负担得起的便携式仪器，价格的一小部分，目前的仪器， 其以已知的准确度和精确度测量颗粒数浓度。设想的 商业仪器将包括商业光学计数器并报告超细颗粒数 浓度和PM2.5质量估计。 第二阶段项目将改进第一阶段系统的性能，完善支持组件， 并将电子器件和部件集成到紧凑的系统中。完整的原型系统将 在实验室和现场条件下进行测试。仪器在一定范围内的精密度和准确度 将使用单分散的实验室气溶胶，使用颗粒尺寸， 范围从5纳米到2500纳米，浓度从接近零到每立方几十万 厘米。将通过极端温度（5°- 40°C）和湿度（5%-95%）。监测性能和稳定性将通过与 在无人值守的情况下操作数周。现场条件下的测量 将与本地大学的接触研究合作进行。作为监查员的验证将在 与空气监测区合作。目标是一个紧凑的，具有成本效益的监测与颗粒 检测限低于5 nm，浓度在10 - 104/cm 3之间时，精密度为±10%， 浓度达到105/cm 3时至少±15%，数据恢复率至少90%。

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%.