Particle loss in a scanning mobility particle analyzer sampling extension tube

Area of Science:

• Nanomaterials science
• Aerosol science and engineering

Background:

• Particle deposition in sampling lines can skew measurements.
• Diffusion is a primary loss mechanism for nanoparticles, affecting size distribution and concentration.
• Electrical and inertial forces have minimal impact on nanoscale particle deposition in sampling lines.

Purpose of the Study:

• To investigate particle losses in sampling lines.
• To quantify the impact of tubing material and length on particle concentration and size distribution.

Main Methods:

• Comparing particle concentrations and size parameters from samples collected with and without inlet extensions.
• Utilizing a scanning mobility particle sizer (SMPS) for particle analysis.
• Testing both rigid graphitic and flexible Tygon tubing materials.

Main Results:

• Number concentration decreased significantly with increased tubing length for both graphitic and Tygon tubes.
• Mean particle size increased for both tubing types at approximately 0.7 m lengths.
• Diffusion losses disproportionately affect smaller particles, altering size distribution.

Conclusions:

• Particle losses in sampling lines are significant and depend on tubing length and material.
• Accurate nanoparticle characterization requires accounting for or minimizing sample line losses.
• Diffusion-driven particle losses impact nanoparticle measurement accuracy.