Abstract
The development of specific passive personal monitors for each volatile form of an element should ultimately lead to a common monitor which can detect any or all forms of that element. Such a device is presented here as a total elemental content passive personal monitor and depends upon diffusion to bring gaseous pollutants into its collecting matrices. The goal of this paper is to show how to compute and limit the ambient concentration error attributed to molecular diffusion approximations for such monitors. The error depends upon the value for the weighted diffusion coefficient used to convert the mass of element collected to ambient concentration. A computed average diffusion coefficient tends to be nonideal, because the relative concentrations of the volatile forms of an element entering the monitor are variable during the work day. Since it is not possible to calculate an exact diffusion coefficient, a finite error will exist between monitor and ambient concentration values. It is shown that total organic chlorine at a vinyl chloride plant can be estimated by use of an average diffusion coefficient without imparting significant error.