Magee Scientific Company
Research into methods for the real-time measurement of optically 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 optically-absorbing ‘Black’ 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 as of this date there are almost 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 AE-16 Aethalometer measuring aerosol ‘Black’ carbon was joined by models offering optical 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 tobacco smoke, wood fire smoke, and fresh diesel exhaust. The AE31 series performs optical analysis at seven different wavelengths from 370 nm to 950 nm, and has found widespread application in studies of atmospheric optics, radiative transfer etc.
In 2001, the ‘Portable’ model of Aethalometer was announced, offering the same optics, electronics, analytical performance and instrument features, but packaged in a smaller chassis with internal battery operation and connection for GPS mobile tracking. This extended 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’ inlet was offered on all models for enhanced performance in locations of high aerosol concentration, as an alternative to the ‘High Sensitivity’ inlet.