Nanoparticle counters and detectors

There is a growing demand to measure even the smallest particles in the size range of nanometers. The main applications of nano-particle counters are aerosol and climate research, air quality monitoring both indoors and outdoors, as well as nanomaterial process monitoring, quality control and optimization.

Single nano-sized particles can not be observed optically. Therefore particles must be grown to optical sizes. By condensing highly saturated working fluid on top of the examined nanoparticles, condensation particle counters (CPCs) can count the grown particles by using an optical particle counter.

The first commercially available product is the Airmodus A09 Particle Size Magnifier. It can be used with any conventional CPC to lower the detection limit even down to one nanometer.

In fall 2011 Airmodus launched a new butanol-based CPC A20. It can be used as stand-alone instrument for measuring particle number concentration in air, or as counter in different kinds of aerosol measurement systems.

References

Instrument characterization

Vanhanen, J., Mikkilä, J., Lehtipalo, K. , Sipilä, M. , Manninen, H. E. , Siivola, E. , Petäjä, T. and Kulmala, M.: Particle Size Magnifier for Nano-CN Detection, Aerosol Sci. Technol., 45: 4, 533-542, 2011

Peer-reviewed articles reporting measurements with Airmodus PSM

Kirkby, J. et al.: The role of sulphuric acid, ammonia and galactic cosmic rays in atmospheric aerosol nucleation, Nature, 476, 429-433, 2011.

Williams, J. et al.: The summertime Boreal forest field measurement intensive (HUMPPA-COPEC-2010): an overview of meteorological and chemical influences, Atmos. Chem. Phys. Discuss., 11, 15921-15973, doi:10.5194/acpd-11-15921-2011, 2011

Benson, D. R., Yu, J. H., Markovich, A., and Lee, S.-H.: Ternary homogeneous nucleation of H2SO4, NH3, and H2O under conditions relevant to the lower troposphere, Atmos. Chem. Phys., 11, 4755-4766, doi:10.5194/acp-11-4755-2011, 2011.

Brus, D., Neitola, K., Hyvärinen, A.-P., Petäjä, T., Vanhanen, J., Sipilä, M., Paasonen, P., Kulmala, M., and Lihavainen, H.: Homogenous nucleation of sulfuric acid and water at close to atmospherically relevant conditions, Atmos. Chem. Phys., 11, 5277-5287, doi:10.5194/acp-11-5277-2011, 2011.

Berndt, T., Stratmann, F., Sipilä, M., Vanhanen, J., Petäjä, T., Mikkilä, J., Grüner, A., Spindler, G., Mauldin III, R.L., Curtius, J., Kulmala, M., and Heintzenberg, J.: Laboratory study on new particle formation from the reaction OH + SO2: influence of experimental conditions, H2O vapour, NH3 and the amine tert-butylamine on the overall process, Atmos. Chem. Phys., 10, 7101-7116, 2010.

Sipilä, M., Berndt, T., Petäjä, T., Brus, D., Vanhanen, J., Stratmann, F., Patokoski, J., Mauldin III, R. L., Hyvärinen, A.-P., Lihavainen, H., and Kulmala, M.: The role of sulfuric acid in atmospheric nucleation. Science, 327, 1243-1246, 2010.