Electrostatic effects in asbestos sampling II: comparison of theory and experiment.
Am Ind Hyg Assoc J 1990 Feb; 51(2):63-69
The degree and type of electrostatic interactions that might occur with electrically charged asbestos (1332214) samplers collecting charged particles were calculated. Charged particle trajectories were calculated for isokinetic, isoaxial conditions in the electrical field of charged asbestos samplers. Electrostatic effects for nonconductive, cowled asbestos samplers included the loss of particles near the edge of the filter and increased variability over the entire filter surface. Particle loss was noted to occur with particles of both polarities. The authors anticipate that the electrostatic effects for conductive cowled asbestos samplers will be somewhat less important than for nonconductive ones. The charge will be spread over the entire cowl or sampler surface and will be symmetrical about the inlet axis. Particles with the same polarity as the sampler will exhibit the highest loss. With increasing flow rate, the electrostatically induced losses will decrease due to the particles spending less time in the high field regions of the sampler. Similarly, increased small scale turbulence and lower air velocities near the sampler inlet are expected to increase such losses.
NIOSH-Author; Sampling-methods; Analytical-methods; Asbestos-dust; Electrostatic-fields; Measurement-equipment; Air-sampling-equipment; Sampling-equipment
American Industrial Hygiene Association Journal