title: Validation of MicroAeth® as a Black Carbon Monitor for Fixed-Site Measurement and Optimization for Personal Exposure Characterization.
abstract: This paper reports on validation experiments with the recently developed microAeth®, a pocket-sized device which is able to obtain real-time and personal measurements of black carbon (BC) aerosol. High reproducibility was observed when comparing the results from six new individual units during fixed-site monitoring out of a window (relative standard deviation [RSD] = 8% ± 5%, N = 1442). The results obtained from the microAeth devices agreed with those obtained from a full size rack mounted Aethalometer, based on both the 1-minute data (R = 0.92, slope = 1.01 ± 0.01, N = 1380) and 24-h average data. The 24-h average of real time data obtained from the microAeths was comparable to the BC concentration obtained from 24-h integrated PM2.5filter deposits, as determined by multi-wavelength optical absorption (R = 0.98, slope = 0.92 ± 0.07, N = 12). Rapid environmental changes in relative humidity (RH) and temperature (T) can result in false positive and negative peaks in the real time BC concentrations, though averages > 1-2-hour are only minimally affected. An inlet with a diffusion drier based on Nafion® tubing was developed in order to use BC data with a high time resolution. The data shows that the diffusion drier greatly reduce the impacts from rapid changes in RH and T when the monitoring system is worn in close proximity to the body (e.g., in the vest pocket).
authors.affiliation: Lamont-Doherty Earth Observatory of Columbia University, New York, NY, USA ; School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Cai
authors.affiliation: Lamont-Doherty Earth Observatory of Columbia University, New York, NY, USA.
authors.forename: Beizhan
authors.initials: B
authors.lastname: Yan
authors.affiliation: Lamont-Doherty Earth Observatory of Columbia University, New York, NY, USA.
authors.forename: James
authors.initials: J
authors.lastname: Ross
authors.affiliation: School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Danian
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Environmental Health Sciences, Mailman School of Public Health at Columbia University, New York, NY, USA.
authors.forename: Patrick L
authors.initials: PL
authors.lastname: Kinney
authors.affiliation: Department of Environmental Health Sciences, Mailman School of Public Health at Columbia University, New York, NY, USA.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Perzanowski
authors.affiliation: Division of Pulmonary, Allergy and Critical Care, Columbia University College of Physicians and Surgeons, New York, NY, USA.
authors.forename: KyungHwa
authors.initials: K
authors.lastname: Jung
authors.affiliation: Department of Environmental Health Sciences, Mailman School of Public Health at Columbia University, New York, NY, USA ; Division of Pulmonary, Allergy and Critical Care, Columbia University College of Physicians and Surgeons, New York, NY, USA ; Division of Pediatric Allergy and Immunology, Columbia University College of Physicians and Surgeons, New York, NY, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Miller
authors.affiliation: Lamont-Doherty Earth Observatory of Columbia University, New York, NY, USA.
authors.forename: Steven N
authors.initials: SN
authors.lastname: Chillrud
keywords: Black carbon; Fixed-site monitoring; Humidity; MicroAeth; Personal exposure