Aerosol instruments classification

Aerosol Instrument Classification. Friedlander (34) classified the range of aerosol instrumentation in terms of resolution of particle size, time, and chemical composition. This classification scheme is illustrated in Figure 3. The ideal instrument would be a single-particle counter-sizer-analyzer. Operating perfectly, this mythical instrument would fully characterize the aerosol, with no lumping of size or composition classes, and would make such measurements sufficiently rapidly to follow any transients occurring in the aerosol system. 

Figure 3. Classification of aerosol instruments in terms of their inherent time, size, and composition resolution. (Adapted from reference 34.)...

One of the stated goals of the NOSH Consortium is to evaluate commercial aerosol instrumentation with the purpose to report on the instrument specifications, ease of use, applicability to different operating conditions, and types or form of data generated to the membership, and to discuss these results with particular emphasis in communicating issues or sensitivities that are relevant to occupational safety and health issues. Major focus areas were in comparing commercial classification and detection instmmentation (1) nano-DMA and long-DMA, (2) ELPI and DMA, and (3) CNC and AE. 

The composition distribution of the particles produced in a laboratory pulverized coal combustor will be explored in this paper using aerosol classification techniques capable of resolving the composition distribution to 0.03 ym diameter. Unlike previous attempts to measure the composition distribution, the particles were classfied directly, without having to resort to resuspension, using calibrated instruments. Experiments were conducted in a laboratory combustor in which operating parameters can be varied over a wide range. Data are presented which demonstrate that the composition of fine particles varies substantially with combustion conditions and does, under some conditions, differ considerably from that of the bulk ash. 

The adaptive spectrometer described in this paper produces either non-imaging, onedimensional or two-dimensional multispectral radiance datasets ( datacube in the case of two-dimensional spectral mapping) for gas or aerosol discrimination and classification. The spectral, temporal and spatial resolution of the data collected by the instrament are adjustable in real time, making it possible to keep the tradeoff between sensor parameters at optimum at all times. The instrument contains no macro-scale moving parts making it an excellent candidate for the development of a robust, compact, lightweight and low-power-consumption device suitable for field operation. 

Aerosol measurement instruments can be conveniently classified according to the type and quantity of information they provide about aerosol properties. The physical principles on which the instniments are based are of secondary importance in this classification scheme, and indeed the instruments can be considered black boxes. This approach makes it possible... 

Cascade impactors are instruments which have been extensively used for sampling and separating airborne particles to determine the aerodynamic size classification of aerosol particles. There are three kinds of cascade impactors inertial impactors, virtual impactors and particle trap impactors. 

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