Evaluation of an infrared open-path spectrometer using an exposure chamber and a calibration cell.
Am Ind Hyg Assoc J 1995 Feb; 56(2):151-157
The use of a controlled exposure chamber and a calibration cell for investigating open path spectrometer measurement accuracy for industrial hygiene application was evaluated. The exposure chamber and five compartment calibration cell were placed directly in the optical path for comparing INFRASAFE open path spectrometer measurements with point sample measurements. The open path measurements were in close agreement, within 10 to 12%, with path averaged concentrations calculated from point samples analyzed using a gas chromatography ECD or a MIRAN. No significant difference was found in measurement accuracy for a variety of path lengths among the experiments performed using the chamber or calibration cell, homogeneous or heterogeneous tracer gas concentrations, and single or reflected beam configurations. The generation of stable and controlled concentrations in both the chamber and calibration cell resulted in low variability among the validation measurements. This ability to control pollutant concentrations along the beam allowed a more direct appraisal of measurement error than possible in outdoor experiments. The five compartment calibration cell provided a successful method to simulate and measure heterogeneous concentrations of sulfur-hexafluoride along a section of the beam. The authors note that this technology offers features that could complement traditional area and personal air sampling methods. They urge that sampling strategies be developed to take advantage of the potential this technique provides for spatially and temporally measuring multiple chemicals in air.
NIOSH-Publication; NIOSH-Grant; Grants-other; Air-quality-monitoring; Exposure-chambers; Air-quality-control; Air-quality-measurement; Environmental-contamination; Environmental-pollution; Air-sampling; Chromatographic-analysis; Sampling-equipment
Environmental Sciences & Engr University of North Carolina CB #7400 Chapel Hill, NC 27599-7400
Other Occupational Concerns; Grants-other
American Industrial Hygiene Association Journal
University of North Carolina Chapel Hill, Chapel Hill, North Carolina