Dust sampler

Lint-free dust as measured by the vertical elutriator cotton-dust sampler described in the Transactions of the National Conference on Cotton Dust, p. 33, J.R. Lynch (May 2, 1970). 

The basic instrumentation in the present work is a Royco Model 225/518 High Concentration Particle Counter. The location of the air inlet and light sensing unit of the instrument in the card room has been described previously (2). The inlet was fitted with a vertical elutriator preseparator designed to prevent particles >15 vin aerodynamic diameter from entering the light sensor. Thus the collection efficiency of this instrumentation as a function of particle size should be similar to that of the Vertical Elutriator Cotton Dust Sampler. 

The algebraic calculations of the distribution parameters included all cells of the histogram while those obtained from the cumulative plots were sometimes based on only a part of the cells. When the distribution was multimodal, the latter calculations included only the values from the distribution with the smaller diameter, and no attempt was made to adjust the percentage count for the number of points in the larger dicuneter distribution(s). Other factors reported are the number of particles per 0.1 ft, the dust concentration measured with the Vertical Elutriator Cotton Dust Samplers (VE), the nature of the cumulative plots, and for multimodal distributions, the percent of particles in the distribution with the smaller dieuneter. 

Textile mill dusts investigated include samples collected using a vertical elutriator cotton dust sampler, seunples of fine dust separated mechanically from carding filter cake material, Scimples collected on electrostatic precipitators in a card room, coarse condenser trash from a card room, and weave room dusts. 

Since its adoption as a cotton dust sampler, the VE has been recognized as a device which sampled other than merely lint-free respirable particles. Bethea and Morey (5) reported that the VE operating under standard conditions (7.4 Lpm) did collect a portion of lint. Several other researchers including Neefus (6), Matlock and Parnell (7.), and Claassen (8) have also reported collections of lint and other particulates greater than 15 vm diameter. 

Experimental Measurements. Besides theoretical modeling of the performance of the VE as a cotton dust sampler, the SRRC has also conducted experimental research on the device. Claassen... 

Carson, G. A. Lynch, J. R. "Calibration of the Vertical Elutriator Cotton Dust Sampler." Presented at the Annual Meeting, A.I.H.A., Boston, Mass. 1973. (Also personal communication to K. Q. Robert). 

To avoid the problems with vacuum cleaner surface dust sampling a special surface dust sampler, HVS-3, was developed (Roberts et al, 1991). The sampler consists of a nozzle that can be adjusted to a well defined distance to the surface, a cyclone that collects the dust particles, an air pump, and an exhaust filter to capture particles that are not retained in the cyclone. SVOCs may break through the cyclone as vapors and a PUF plug can be inserted after the cyclone. HVS-3 has been modified to ensure a more constant suction pressure and volume, and a known sampled area (Gyntelberg et al, 1994). The design and use of the HSV3 has now been standardized (ASTM, 1997, D 5438-94). 

Auother dust sampler that uses a haud-held vacuum cleaner but is capable of collectiug large dust samples was desigued by Rudel et al. (2001). The method employs a Eureka Mighty-Mite vacuum cleaner (8 A) (The Eureka Company, Bloomington, IL, USA) with the dust bag replaced by a 19-uun x 90-mm cellulose Soxhlet extraction thimble contained in a special PTFE sampling module. 

USEPA (1996b). Evaluation of Dust Samplers for Bare Floors and Upholstery, Report No. 600/R-96/001, National Exposure Research Laboratory, Research Triangle Park, NC, USA. 

For the analysis of radionuclides in airborne dust, the dust is collected on a filter using a dust sampler. Iodine in the air is collected on an active carbon filter using a dust sampler. Tritium exists in the form of vapour (HTO) or gas (HT) in the air. The HTO is absorbed on silica gel HT is changed to HTO using a palladium catalyst and then the HTO absorbed on silica gel. Radioactive noble gases such as Kr are absorbed on an active-carbon trap cooled with liquid nitrogen. 

Air particulate samplers are usually classified as low-volume air samplers or high-volume air samplers. There are, in addition to these classifications, dust samplers that consist of a combination of a low-volume suction pump and a movable filter-paper system. Characteristics of these samplers are as follows ... 

A more detailed investigation of commercially available filter materials on another air-dust sampler which maintains flow rates of more than 850 m /h over the whole sampling period recently revealed nuclide-specific collection efficiencies of more than 95% for one single filter layer (Arnold et al., 1994). 

Vincent, J. H., Emmett, P. C., and Mark, D., "The Effects of Turbulence on the Entry of Airborne Particles into a Blunt Dust Sampler", Aerosol Sci. Tech., 4,11... 

Apart from these fundamental improvements via procedural change, a number of further measures are specified in Table 9.15, with which a sustainable reduction of the emissions during ore smelting can be achieved (Elgersma etal. 1995). For air pollution abatement from heavy metals, the use of highly effective woven filters as a replacement of electrostatic dust samplers... 

Because of the relatively large amount of dust necessary for substance-specific analysis, stationary samplers capable of sampling large volumes of air have to be used to collect sufficient material for an accurate analysis. The already mentioned Gravikon VC 25, furnished with a fine-particle sampling head, is an example of a sampler for this task [6-109]. Like other fine dust samplers, this stationary device meets the requirements of the "Convention of Johannesburg (see Section 2.10). 

Inhalable dust sampler (type I.O.M. sampler), available from SKC Ltd., Blandford Eorum, Dorset, UK. 

Respirable dust sample A sample collected with an approved coal mine dust sampler unit attached to a miner, or so positioned as to measure the concentration of respirable dust to which the miner is exposed, and operated continuously over an entire work shift of such miner. 

Figure 21.2 Personal dust sampler. (Courtesy Casella London Ltd)...

Grave. Decoration on glass, by sandblasting to various depths. Gravimpinger. A simple gravimetric dust sampler developed at British... 

Techniques for unknown pollutants involve collecting a sample over a period of time and returning it to the laboratory for detail chemical analysis. Collection can be in containers such as bladders, bags, cylinders, bottles, syringes or on chemically absorbent materials such as activated charcoal or silica gel. Those methods which use containers may lose some of the collected gases or vapours by adherence to the inside of the container. The chemical absorbers are usually contained in small glass or metal tubes connected to a low-volmne sampling piunp and can be worn by a worker in a similar fashion to the personal dust samplers. 

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