Investigating Principles of Workroom Exposure.

摘要

The study was conducted in an experimental room with mixing ventilation and a tracer gas was injected at a constant rate. Concentration was monitored at 144 points with a photoionization detector attached to an automated sampling system. The research was designed to use three constant dilution air flow rates, 5.5, 3.3, and 0.88 m3/min; but use of the lowest air flow rate was not feasible due to excessive monitoring time requirements. The number of sampling points required to characterize concentration distribution within the experimental room was determined by comparing concentration isopleths from subsets of data containing from 100 to 150 points. No substantial differences in isopleth shape or magnitude were observed over this range. Hence, a 3-dimensional network of 144 points was utilized. Two air inlets types were studied: a wall jet (WJ) with its center 2.12 m above the floor and a vaned diffuser in the center of the ceiling (CD), just above the tracer gas source.