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

一种脉冲凝结粒子计数器 具有成本效益的超细空气颗粒物监测 摘要 该项目将开发和验证一种新的方法，用于负担得起的监测数量集中 空气中的超细颗粒物。超细颗粒明确地与健康有关，但不能被检测到 成本更低的传感器。我们的方法是使用绝热膨胀的脉冲凝聚粒子计数器 结合单颗粒计数。我们的第一阶段结果表明，该方法是可靠的 连续运行数月，与昂贵的研究级冷凝颗粒的符合率为±10% 柜台。我们的目标是一种负担得起的便携式仪器，价格只有目前仪器成本的一小部分， 它以已知的准确度和精密度测量颗粒物的数量浓度。预想的 商用仪器将包括商用光学计数器和报告超细粒子数量 浓度和估计的PM2.5质量。 该二期工程将提高一期系统的性能，完善支撑部件， 并将电子设备和组件集成到一个紧凑的系统中。完整的原型系统将是 在实验室和现场条件下都进行了测试。仪器精密度和一定范围内的粒子准确度 大小和浓度将用单分散的实验室气雾剂进行评估，使用颗粒大小 范围从5纳米到2500纳米，浓度从接近零到每立方米数十万 厘米。仪器的稳健性将通过在极端温度(5°- 40°C)和湿度(5%-95%)。监控性能和稳定性将通过与 在数周的无人值守操作中配置台式仪器。现场条件下的测量 将与当地一所大学合作进行接触研究。作为监视器的验证将在 与空气监测区合作。目标是一种紧凑、经济实惠、带有粒子的监视器 检测下限小于5 nm，浓度在10-104/cm3范围内的精密度为±10%，精密度为 浓度达到105/cm~3时，最小为±15%，数据回收率至少为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%.