Aerosol spectrometers

Together with the radon daughter measurements, nearly continuous measurements of the ventilation rate are performed by means of the release of N2O tracer gas and observation of its decay with an infrared spectrometer (Miran 101). Furthermore the aerosol concentration and size distribution are monitored every 20 to 30 min with an automated aerosol spectrometer (Raes et al.,1984). 

Note DMS differential mobility spectrometer, SMPS scanning mobility particle sizer, CPC condensation particle counter, TDMPS twin differential mobility particle sizer, DMPS differential mobility particle sizer, OPC optical particle counter, APS aerodynamic particle sizer, MAS mass aerosol spectrometer, LAS-X optical laser aerosol spectrometer, ELPI electrical low pressure impactor... 

Tammet, H., Mirme, A. and Tamm, E. (1998) Electrical aerosol spectrometer of Tartu University. Journal of Aerosol Science, 29, S427-8. 

Aerosol centrifuges are useful in the laboratory but have little application in air cleaning. When care is taken so that the aerosol enters the rotating annulus at a single point, the units are often called aerosol spectrometers. A discussion of the calibration and operation of the popular Stober spectrometer design (Stober and Flachsbart, 1969) is given by Martonen (1989). 

Tuch et. al. [231] ran a Mobile Aerosol Spectrometer (0.1 to 2.5 pm) and an Electrical Aerosol Spectrometer (0.5 to 10 pm) side by side for 6 weeks and found both to be reliable with almost identical results. Total number counts agreed with results from a Condensation Particle Counter. 

Kaye, B.H. Alliet, D. Switzer, L. Turbitt-Daoust, C. The effect of shape on intermethod correlation of techniques for characterizing the size distribution of a powder II. Correlating the size distribution as measured by diffractometer methods, TSI-amherst aerosol spectrometer, and coulter counter. Part. Part. Syst. Charact. 1999, 16, 266-272. 

In addition to the TSP measurements some fractions of nanoparticle emissions in the range of 30 to 400 nm were done with Scaning Mobility Particle Sizer (SMPS), and particles in the range of 400 nm to 20 jim with an optical Aerosol Spectrometer. The sampling point in the dilution tunnel was close to the gas sample point. 

Mitchell JP, Nagel MW, Wiersema KJ, et al. Aerodynamic particle size analysis of aerosols from pressurized metered-dose inhalers comparison of Andersen 8-stage cascade impactor, next generation pharmaceutical impactor, and model 3321 aerodynamic particle sizer aerosol spectrometer. AAPS PharmSciTech 2003 4 E54. 

All measurements were made using a Particle Measuring Systems Inc, Laser Aerosol Spectrometer Model LAS-X. The LAS-X Is a light scattering Instrument which uses a He-Ne laser. The gas sampling... 

An Electrical Aerosol Spectrometer (EAS) was developed in the Institute of Environmental Physics of the University of Tartu as a result of the 20-year research and developing work. The latest version of EAS has been built by AIREL Ltd. 

Table I, provided yet another instrumental approach for balloon experiments intended to measure the extinction of solar radiation by stratospheric aerosol. Spectrometer 4, Table I, based on the use of a pyroelectric vidicon image device, was developed to measure the strong absorption bands of non-isonuclear molecules ( 2-5 ym range). Recently we have developed spectrometer 5, Table I, based on the use of a self-scanned solid state pyroelectric array sensor. The main advantages of this sensor, over the pyroelectric vidicon, are its improved sensitivity and reduced channel-to-channel cross-talk.

Gibson, H., Vicent, J. H., and Mark, D., "A Personal Inspirable Aerosol Spectrometer for Applications in Occupational Hygiene Research", Ann. Occup. Hyg., 31, 463 (1987). 

In view of the influence of particle size on inhalation radiation exposure, some collectors of discrete particle sizes are deployed, typically for research rather than routine monitoring. Impactors with metal plates or Mylar foils that are sprayed with silicone to reduce particle bounce (ACGIH 2001) have proven useful, but can challenge radioanalytical chemistry preparations. An aerosol spectrometer with a series of metal screens (ERA 2004) may present less of a chemical preparation problem. 

Figure 5.8. The Timbrell Aerosol Spectrometer uses a tapered elutriation chamber to lower the flow rate along the chamber so that ever smaller fineparticles can settle to the bottom.

A. Goetz, The Aerosol Spectrometer, A New Instrument for the Analysis of Airborne Particles in the Sub Micron Range, Public Works Magazine (February 1959), 91—93. Commercial information on the Goetz aerosol spectrometer is available from the Zimney Corporation, 1900 South Myrtle Avenue, Monrovia, California 91016. 

Another aerosol spectrometer is manufactured by TSI Incorporated. Their instrument is known as the Aerodynamic Particle Sizer (APS). This system operates at subsonic flow conditions, and has a lower rate of count than the Aerosizer . The performance of the instrument has been documented in various publications [59, 60, 61]. In... 

With the new equipment it is claimed that both types of errors are eliminated by using overlapping laser beams, producing one double crested beam profile. Each particle then creates a single, continuous signal that has two crests. Particles with only one crest are phantom particles, or with more than two crests are coincident errors and are logged for concentration calculations, but are not used in building the size distribution. The commercial development of aerosol spectrometers is a very active area of research, and one should check for the latest information with the manufacturers of such instruments. 

Brand P, Ruoh K, Gebhart J. Performance of a mobile aerosol spectrometer for an in situ characterization of environmental aerosols in Frankfurt city. Atmos Environ... 

---