Recent developments in aerosol measurement techniques and the metrological issues

Abstract

A small error in the aerosol measurements can lead to a considerable influence on our understanding towards its impact on climate. To better simulate aerosol effects on the earth's radiation budget, the chemical and physical characterizations of aerosol particles with accurate measurements have been a key interest in the aerosol research for last several decades. Recent advances in the chemical characterization of aerosols at bulk and molecular levels, and their physical characterization, such as size distribution, hygroscopicity, and cloud condensation nuclei (CCN) activity have improved our knowledge to better understand the aerosol sources, concentration distributions, atmospheric processing and their potential climate impacts. Apart from the complexity of atmospheric aerosols, because of the limited availability of aerosol certified reference materials, traceability data and measurement protocols, it is still a challenging task to measure the aerosol properties with reduced uncertainty. The recent developments on aerosol analytical techniques (on-line and off-line), which include gas chromatography/ flame ionization detector (GC/FID) /mass spectrometry (MS)/ isotope ratio mass spectrometry (irMS), ion chromatography (IC), organic carbon/elemental carbon (OC/EC) and water-soluble organic carbon (WSOC) analyzers, and physical measurements using scanning mobility particle sizer (SMPS), hygroscopicity tandem differential mobility analyzer (HTDMA) and cloud condensation nuclei-counter (CCN-C) are discussed with the metrological issues in the measurements. The importance of aerosol metrology is highlighted giving the data obtained from the laboratory studies and aerosol field campaigns.

Organic and inorganic components of aerosols over the central Himalayas: winter and summer variations in stable carbon and nitrogen isotopic composition

“…Magnesium (Mg 2+ ) ion concentrations in the samples were found to be less than the detection limit. It must be mentioned here that the analytical errors were below 1.3 % based on the triplicate analyses of the filter sample (Aggarwal 2010;Aggarwal et al 2013).…”

Measurement of Benzo(a)pyrene in PM10 Collected in New Delhi

“…Any type of small error in the measurement of aerosols can have a strong impact on its understanding. Therefore, to understand the physical and chemical properties of aerosols, their measurements should be accurate [30]. National metrology institute (NMI) should provide the calibration requirements of industries involved in the gas and aerosol metrology.…”

Impact of glycol‐based solvents on indoor air quality—Artificial fog and exposure pathways of formaldehyde and various carbonyls

“…A wide spectrum of online aerosol instruments is used by atmospheric scientists to achieve real‐time, size‐resolved measurements of aerosol. These instruments determine aerosol sizes based on optical, mobility, or aerodynamic techniques and can achieve a time resolution of a few minutes or less 30,31 . Such time resolution is sufficient to monitor rapidly evolving aerosol generated by AFM.…”

“…These instruments determine aerosol sizes based on optical, mobility, or aerodynamic techniques and can achieve a time resolution of a few minutes or less. 30,31 Such time resolution is sufficient to monitor rapidly evolving aerosol generated by AFM. Chemical analysis for rapidly evaporating aerosol can be highly challenging.…”