A new approach to black carbon measurement

Atmospheric Particulate Matter (PM) or aerosols play a key role in the atmosphere as particles cause visibility reduction, act as clouds condensation nuclei, affect the global climate change and are responsible for adverse health effects.  Carbonaceous Aerosol (CA), typically emitted by incomplete combustion of fossil fuels related to traffic, industrial processes and domestic heating, is one of the main components of PM especially in urban environments and it is very important from the climate change point of view too, since Elemental Carbon (EC), which, depending on the technique adopted to reveal it, can also be called Black Carbon (BC), is the primary responsible of light absorption and of the direct radiative effect of aerosol on climate.

Nevertheless, the measurement of CA composition, though prescribed by national and European regulations, is at the moment a “work in progress” and no methodology appears at the same time both of simple use and sufficiently robust. At the state of the art the measurement of light absorbing aerosols is still challenging, even though filter-based on-line techniques (e.g. the aethalometer; the particle soot absorption photometer; the multi-angle absorption photometer, among others) are widespread but it is widely recognized that they are affected by measurement and sampling artifacts which must be accurately managed by skilled personnel. 

In this context Dado Lab have created a methodology for measuring the concentration of black carbon that can adopt many advantages of commercially available instruments, in particular the capability of obtaining a "real time" measurement by means of non-destructive techniques, and that can at the same time overcome some of their limits by exploiting different physical principles and allowing its integration into a sequential sampler.

The result is the Giano BC1, a PMx sequential sampler with a 21 filter capability and built-in BC optical sensor for real-time measurement made directly on the sample during its collection on the field.
Since the particulate matter fractions are collected on classic 47mm round filters, commonly available on the market, it is also possible to make further analysis on the sample for chemical speciation.