Particle loss in a scanning mobility particle analyzer sampling extension tube.

Deposition of particles in sampling lines may occur due to various physical forces. Particles in the nanoscale are not highly susceptible to inertial or sedimentary deposition, and electrical losses are reportedly controlled by using conductive tubing. Particle losses from diffusion affect size distribution and number concentration. Selectively removing the smallest particles has the effect of increasing the statistical measure of particle size-the geometric mean-while decreasing number concentration and geometric standard deviation. Quantification of losses is necessary to interpret or correct the data. Sample loss from a rigid graphitic or flexible Tygon tube attached to a scanning mobility particle sizer inlet was investigated during sampling at the Center for Nanophase Materials Sciences. Mean concentrations and particle size parameters determined from samples collected with and without sample inlet extensions were compared. Number concentration decreased and mean particle size increased for both tubing types at lengths of approximately 0.7 m.