Measurement and Imaging of Gases in Industrial Environments with the Infrared Gas Cloud Scanner

Abstract

Usual gas sampling methods for checking compliance with threshold limit values do not provide information on the cause of the observed exposure, nor is gas dispersion being visualized on-line. For effective improvement of noncompliance work situations, such information on causes and gas dispersion patterns is indispensable. The infrared gas cloud (IGC) scanner was developed for fast, remote, and quantitative identification of (hazardous) gases by imaging of gas dispersion in the work environment. The application of the prototype IGC scanner to three real problems is described in this study. The first application is a laboratory investigation on the influence of ventilation parameters on the exposure of welders to welding fumes. As a result the problem of protecting very mobile welders could be solved. The second case describes carbon disulfide (CS₂) measurements by IGC scanning in a rayon factory. We found that the heavy CS₂ gas could spread like a blanket on the floor of the factory and that IGC-determined concentrations at aspiration height compared well with independent personal measurements. Third, the IGC scanner was used to monitor surface treatment in the polyester industry, where in a number of cases high exposure to volatile organic components (VOCs) was identified. Each application showed the IGC scanner to be a successful, cost-effective instrument. Therefore, the scanner could be a useful addition to industrial hygiene facilities for controlling and improving the work environment as a rapid and powerful technique with advantages over existing air sampling instruments. ter Kuile, W.M.; Knoll, B.; Hesselink, P.G.M.: Measurement and Imaging of Gases in Industrial Environments with the Infrared Gas Cloud Scanner. Appl. Occup. Environ. Hyg. 8(1):46-54; 1993.