| Description |
The goal of this study was to develop a new design for the Critical Orifice Personal Sampler (COPS) that is capable of sampling at constant flowrate (+/- 10% of the initial flowrates) for 8-hour periods. By substituting an independent valve system for the septum and by coating the samplers with a perflex rubber, these goals were attained. The second goal of this study was to compare the COPS sampler's effectiveness with that obtained with gas sampling bags. The COPS proved to be capable of achieving relatively high recoveries (89-102%) of sulfur hexa-fluoride when sampling from test atmospheres of 0.5X, l.OX, and 2.OX and the PEL (1000 ppm) at 53% relative humidity and ambient temperature of 25 degrees centigrade. The COPS is a very practical and useful application of the critical orifice principle. It is felt that these samplers can become a much more viable and useful method for gas sampling. The COPS, while providing similar results as the gas bag method, is less cumbersome to use, is versatile in application, and permits quick analysis. Since the lightweight COPS can be placed in a pocket or attached to a belt, the problems with workers wearing them are minimized. These samplers can be used to sample for any gas in a relatively clean workplace environment. Gases presented collected on charcoal tubes, such as anesthetic gases, would be good candidates for method development in the future. In those applications, such as the sampling and analysis of sulfur hexafluoride, where the analysis can be conducted by infrared analysis, field samples can be collected and analyzed on the same day. This provides the industrial hygienist with an efficient, effective tool to evaluate workplace exposures quickly and accurately without waiting weeks for samples to be returned from the laboratory. |
