Magee Scientific Corporation
Magee Scientific is the originator of the Aethalometer®, the most-widely-used instrument for the real-time measurement of Black Carbon aerosol particles in the atmosphere. These particles reduce visibility; adversely impact human health; and contribute to regional and global climate change. Aethalometers are installed on all continents: from cities in China to the South Pole, from the Sahara Desert to the Amazon basin.
Research into methods for the real-time measurement of light absorbing aerosols began in Berkeley in approximately 1978. The first-ever Aethalometer® was deployed in a field study in the summer of 1980: the first aircraft measurements were made in 1982, and in 1986 an Aethalometer started making measurements of aerosol Black Carbon at the most remote location on the planet, the South Pole Observatory. Magee Scientific Company was established that same year to develop the Aethalometer further and make it available to the aerosol research and monitoring community. From 1999 to 2001, the instruments were also distributed by Andersen Instruments Inc. and subsequently Thermo Environmental Instruments as identical hardware, but with the chassis painted in ‘Andersen’ or ‘Thermo’ colors and name. Distribution by Andersen/Thermo has now been discontinued.
Aethalometers have been used in increasing numbers over the years: a large number of reports have been published in the open scientific literature. A compendium of these reports is found at the literature link.
The History of the Aethalometer
The Aethalometer® is the foremost instrument for the real-time measurement of light absorbing Black Carbon or ‘Elemental’ carbon aerosol particles. It was first conceptualized in 1979; prototypes and variations evolved during the 1980’s on research projects at remote locations; the first commercial unit was shipped in 1986; production was transferred to Europe in 1995 and Aerosol d.o.o. company founded in 2007. As of this date there are more than one thousand Aethalometers in use on all continents from the Sahara Desert to the South Pole, from Brazil to Tibet, from the streets of New York City to the mountaintop of Mauna Loa, Hawaii.
In 1997, the basic AE16 Aethalometer measuring aerosol Black Carbon was joined by models offering light analysis at additional wavelengths. The AE21 series adds analysis in the near-ultraviolet at 370 nm, which is found to respond with great sensitivity to aromatic organic species such as are found in wood smoke. The AE31 series performs light analysis at 7 wavelengths from 370 nm to 950 nm, and has found widespread application in studies of source apportionment, atmospheric optics, and radiative transfer.
In 2001, the Portable Aethalometer was announced, offering the same electronics, analytical performance and instrument features, but packaged in a smaller chassis with internal battery operation. A GPS unit can be connected to the Portable Aethalometer, extending the Aethalometer applications in the area of public health and epidemiological studies, by allowing for real-time measurements of carbon particulate concentrations on buses and trains, in living and working areas, in hospitals, airports and other public spaces; and for mobile mapping.
In 2002, the ‘Extended Range’ version was offered on all models for enhanced performance in locations of high aerosol concentration, as an alternative to the ‘High Sensitivity’ version.
In 2008, the development of a new Aethalometer: the ‘Next Generation’ Aethalometer®, Model AE33. This development incorporates scientific and technical advances designed to offer improved measurement performance, user features, communications and interface, and the ability to perform routine performance tests to verify correct operation. Most importantly, the new instrument incorporates the patented DualSpot™ measurement method. This provides two significant advantages: elimination of the changes in response due to ‘aerosol loading’ effects; and a real-time calculation of the ‘loading compensation’ parameter which offers insights into aerosol optical properties.