Dichotomous samplers modified for use with electron microscopy

Technical Report · Sun Dec 31 23:00:00 EST 1989

OSTI ID:6146579

Mamane, Y; Dzubay, T G

Large sulfate artifacts up to 2 micrometers in diameter were observed by scanning electron microscopy for the fine particle fraction collected in dichotomous samplers. The artifacts were attributed to small liquid particles that piled up on the filter, coalesced, and later dried as larger particles. Such artifacts were eliminated when particles were collected in a modified dichotomous sampler in which 80% to 90% of the airflow was diverted from the fine fraction filter. This airflow diversion technique was used successfully with both virtual-impactor and tandem-filter types of dichotomous samplers.

• Research Organization: Environmental Protection Agency, Research Triangle Park, NC (USA). Atmospheric Sciences Research Lab.
• OSTI ID: 6146579
• Report Number(s): PB-91-116830/XAB; EPA--600/J-90/183
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
AEROSOL MONITORING
AIR POLLUTION
AIR POLLUTION MONITORING
AIR SAMPLERS
ELECTRON MICROSCOPY
EQUIPMENT
MICROSCOPY
MODIFICATIONS
MONITORING
OXYGEN COMPOUNDS
PARTICLE SIZE
POLLUTION
SAMPLERS
SCANNING ELECTRON MICROSCOPY
SIZE
SULFATES
SULFUR COMPOUNDS