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Continuous optical monitoring of asbestos in air.
The John B. Pierce Foundation of Connecticut, Incorporated, 1980 Aug; :1-6
The development of a continuous optical monitor for determining airborne asbestos (1332214) fibers is described. The initial design of the device is reviewed along with later modifications implemented to increase sensitivity and specificity. The final device consists of eight platinum wire electrodes, a glass tube, and a helium neon laser. Two high voltage transformers energized with 400 hertz sinusoidal voltages also are used. The electric field within the glass tube is analyzed by a computer. For sampling, the laser beam shines down the glass tube, and light reflected by the particles within the lumen of the tube passes up through the aperture of the the photomultiplier cathode. Air is drawn up through the tube at an adjustable flow rate. The glass tube does not distort the electric field, and a uniform electric current ensure that polarized fibers will not migrate to the tube walls and that the forces on the fibers will be the same anywhere within the lumen.
NIOSH-Grant; Control-technology; Air-contamination; Analytical-instruments; Equipment-design; Asbestos-dust; Fibrous-bodies; Air-sampling-equipment; Optic-system
Biophysics Division John B Pierce Fdn Laboratory 290 Congress Avenue New Haven, Conn 06519
Final Grant Report
NTIS Accession No.
The John B. Pierce Foundation of Connecticut, Incorporated
John B. Pierce Foundation Lab, Inc., New Haven, Connecticut
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division