AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Next-Generation Air Monitoring - A Review of Portable Air Pollution Sensors
PAUL A. SOLOMON, Margaret MacDonell, Ron Williams, Eben Thoma, Dena Vallano, Michelle Raymond, Olson David, US EPA
Abstract Number: 405 Working Group: Portable and Inexpensive Sensor Technology for Air Quality Monitoring
Abstract New technologies and architectures for sensing gases and particles in air are emerging, for criteria pollutants, air toxics, and greenhouse gases. These technologies are generally designed to be mass-fabricated through innovative processes (e.g., microfabrication) and are: 1)small; 2) able to autonomously and directly read pollutant levels; 3) have low power consumption; and 4) support flexible deployment options [White et al. Environmental Manager, pp. 36-40, May 2012]. These traits translate to reduced total cost of ownership, enabling a higher density of air pollution measurements and personal exposure applications to be considered.
Measurements from, the existing national air monitoring network can be used to infer community-wide concentrations of ozone and fine particle (< 2.5 micro-meter) mass. However, other pollutants directly emitted into the air, such as elemental carbon, coarse particles (between 2.5 and 10 micro-meter), carbon monoxide (CO), nitrogen oxides (NOx), and various air toxics have been shown to have much higher variability between regional air pollution monitors compared to pollutants like ozone that are secondarily formed in the atmosphere. Portable air pollution sensors can potentially provide more location-specific information desired by individuals, and communities. There is also a desire to use portable sensors to monitor indicator pollutants or classes of pollutants, like methane and total volatile organic compounds (VOCs), as well as nuisance pollutants, like hydrogen sulfide (H2S) and ammonia, which indicate the presence of pollution sources.
Current technologies for portable sensors for air pollutant gases reviewed include: electrochemical, metal oxide, spectroscopic, ionization, and pellistor sensors. Current technologies for portable particle sensors include: light scattering, light absorption, and those based on a change in frequency of an oscillating impaction surface. Attributes that indicate the appropriateness of these technologies for sensing the pollutants mentioned above will be discussed, including: estimated range of measurement, selectivity (when applicable), appropriate deployment platforms, response and recovery time, battery lifetime, and expected range of acceptable operating conditions. Information will also be provided about the potential of emerging sensor technologies to address the deficiencies in the abilities of existing sensor technologies to measure these pollutants.