Methods of Aerosol Measurement before the 1960s

Abstract

EICHFNWFG 6, D-57392 S< HMALL LPIRtR(r, GERMANY ABSTRACT. The time period before the 1960s can be described as the classical age of aerosol science and aerosol measurement. The measurement philosophy during this period was different from that of the period after the 1960s. Particle number concentration was considered the most important parameter. Optical microscopy was the determinative procedure for sample evaluation, for particle counting, and for size measurement. The most frequently used sampling methods were impaction and impingement, thermal and electrostatic precipitation, and filtration. Condensation samplers, as well a s manual condensation nuclei counters, were used also. Manual and simple light scattering and light absorption methods played a n already important role. Ultramicroscopy and nephelometry were commonly used methods. Elutriators and aerosol centrifuges were used for determining aerodynamic particle sizes, particle shape factors, and mass size distributions. Chemical aerosol analysis was in a developing state. Silica, silicates, and heavy metals were the most often detected dust and aerosol components. Titration, colorimetry, photometry, and polarography were the most commonly used analytical procedures. Practically no automatic or computer-supported measurement or analytical equipment was available a t this time. Sampling instruments often were made in the laboratory, rather than produced commercially.

A review of coarse mineral dust in the Earth system

“…There have been widespread inconsistencies in the definition of the boundary diameter that separated the fine and coarse modes (e.g., Heintzenberg, 1989;John et al, 1990;Kulkarni et al, 2011). Before the late 1970s, most studies defined this boundary at 2 µm (Danes, 1954;Heintzenberg, 1989;Spurny, 1998;Walton, 1954;Whitby, 1978;Willeke and Whitby, 1975). Subsequent studies re-defined the boundary diameter between fine and coarse modes to be at 1 µm (Friedlander, 2000;Mahowald et al, 2014;Ansmann et al, 2017), 2.5 µm (Seinfeld and Pandis, 2006;Zhang et al, 2013;Pérez García-Pando et al, 2016), 4 µm (e.g., Rajot et al, 2008), or at 5 µm (Kok et al, 2017;Adebiyi and Kok, 2020).…”

Air Pollution Monitoring Strategies and Technologies for Urban Areas

“…Other early air quality monitoring techniques focused on the measurement of airborne particles. The use of fibrous filters for sampling airborne particles was invented around 1920 (see [23]) and became standard for ambient air quality monitoring after 1940. The method of manually weighing a filter prior to and after sampling a defined volume of air is still in use, and it is currently the basis of reference methods for the determination of PM 10 and PM 2.5 in the EU and US.…”

The Aitken counter: Revisiting its design and performance characteristics

“…The first was a tabletop dust counter that utilized heterogeneous nucleation to grow particles in order to be detected by the human eye (Podzimek 1989). This phenomenon was first discovered by Paul-Jean Coulier in 1875 and discovered independently by John Aitken in 1880 (Spurny 1998). The tabletop version was problematic because it was not sufficiently portable to make ambient air measurements across the country and around the world (Aitken 1890).…”