Comparative testing of an FTIR remote optical sensor with area samplers in a controlled ventilation chamber.
Yost-MG; Xiao-HK; Spear-RC; Levine-SP
Am Ind Hyg Assoc J 1992 Oct; 53(10):611-616
The ability of a portable Fourier transform infrared (FTIR) remote optical sensor to monitor chemical exposures in indoor environments was evaluated. The FTIR sensor was deployed in a 143 cubic meter test chamber designed to produce uniform dilution ventilation in a horizontal plug flow configuration. The sensor was used to monitor acetone concentrations in the chamber under homogeneous and heterogeneous dispersion conditions at airflow rates of 3 and 6 centimeters per second, equivalent to 15 and 30 air changes per hour. Acetone was released as a point source at initial concentrations of 1 to 1500 parts per million. The acetone concentrations were monitored over scan times of 30 to 90 minutes and compared with parallel measurements obtained by a custom built computer controlled multipoint flame ionization detection (FID) system. Over all conditions, the FTIR measurements came within 50% of the FID array data, most were within 15%. The slope of a regression plot of the FTIR sensor data against the FID system data obtained under homogeneous dispersion conditions was 1.15, which was significantly different from unity. The regression line went through the origin. The correlation coefficient was 0.97. The slope of the regression line obtained under heterogeneous dispersion conditions was 1.09. The slope was statistically the same as unity, but the data showed higher variability, as evidenced by a correlation coefficient of 0.85. The intercept was zero. The authors conclude that the FTIR remote optical sensor can be a viable technique for indoor air monitoring. Comparative data obtained under heterogeneous dispersion conditions shows more variability than under homogenous dispersion conditions. The difference may reflect the limited spatial and temporal resolution of the FID array relative to the FTIR sensor.
NIOSH-Publication; NIOSH-Grant; Grants-other; Infrared-spectrophotometry; Air-monitoring; Vapor-detectors; Laboratory-testing; Air-flow; Monitoring-systems
Environmental & Indust Health University of Michigan 1420 Washington Heights Ann Arbor, MI 48109-2029
Other Occupational Concerns; Grants-other
American Industrial Hygiene Association Journal
University of Michigan at Ann Arbor, Ann Arbor, Michigan