A new personal sampler for organic vapors

Abstract

This paper describes the evaluation of a new personal sampler for organic vapors which is totally different from traditional sampling techniques using pumps and adsorption tubes. Sampling of organic vapors is effected by collection on an adsorption substrate contained within a small passive sampler worn by the worker. The collection element is removed from the sampler and subsequently analyzed for organic vapors. The results are equated with the time-weighted-average concentration of contaminants in air. This new sampling device circumvents inherent errors generally associated with sampling pumps and tubes; e.g., changes in pumping rates and variable pressure drops across adsorption tubes. Applications of the sampler were demonstrated on various concentrations of benzene, methyl isobutyl ketone, isooctane, butyl acetate, methyl chloroform, trichloroethylene, butanol and solvent mixtures. Variables studied included the effects of temperature, charcoal lot, and air velocities. In addition, the occurrence of "breakthrough" and effect of time on sample stability were investigated.

New Results on the Vibrating String with a Continuous Obstacle.

“…This formula shortens considerably a previous proof [2] of continuous dependence on data, and is the key for the numerical scheme studied in §3. We shall give in §4 a regularity theorem in spaces of bounded variation, in the case of a general concave obstacle.…”

“…When the string does not touch the obstacle, its motion satisfies the wave equation, and thus (2) supp 0 u C { (X, t): U (X, t) = <p (X)} .…”

“…It is not enough to suppose that conditions (1), (2) and (3) are satisfied, as nothing has been said of the evolution of the energy of the string during the collision with the obstacle.…”

Survey on research needs on personal samplers for toxic organic compounds

“…This directive (9,47) permits a maximum allowable 8-hr TWA exposure of 1 ppm to vinyl chloride and a maximum permissible exposure of 5 ppm for no more than 15 min. A method for measuring the exposure of personnel to vinyl chloride has been developed which utilizes the permeation technique for sampling (18) The abundant literature on the development strategy for pollution dosimetry is a subject of several papers, monographs, and books (25,32,46,(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59).…”

AMEC multigas passive sampler: a green product for cost-effectively monitoring air pollution indoors and outdoors

“…Since then, passive samplers have been developed for monitoring air pollution in the ambient environment (including vegetation canopies study), work place, and indoor environment, which include air pollutants such as SO 2 [2,3], NO 2 [4,5], H 2 S [6,7], NO x [8], O 3 [9], VOC [10], aldehyde [11] etc.…”