Estimates of errors in anisokinetic sampling of particulate matter

Journal Article · Tue Mar 01 04:00:00 EST 1977 · J. Air Pollut. Control Assoc.; (United States)

DOI:https://doi.org/10.1080/00022470.1977.10470416· OSTI ID:5042390

Selden, Jr, M G

The mass concentration of particulate matter suspended in a flowing gas stream (stack gas) is commonly measured by aspirating samples of the particle-laden gas into a nozzle (aligned to have its suction orifice facing the flow). The mass concentration (e.g., grains per standard cubic foot of gas) is normally computed from the ratio of the mass of particles collected to the volume of gas sampled. The mass concentration will be correctly computed, provided that precautions are taken not to alter the samples. A major precaution is to assure negligible sampling bias by isokinetic sampling with proper alignment of a sharp edged sampling nozzle. When the mean aspiration velocity differs from the upstream gas velocity (anisokinetic sampling), the gas flow is disturbed, causing a change in particulate matter concentration within the gas entering the sampling nozzle. The error in particulate matter concentration, as a result of anisokinetic sampling, is a function of the particle sizes, nozzle diameter, particle density, gas density, the sampling speed, the speed of the upstream flow, and the viscosity of the gas (eight independent variables).

• Research Organization: Pollution Measurement Corp., Chicago
• OSTI ID: 5042390
• Journal Information: J. Air Pollut. Control Assoc.; (United States), Journal Name: J. Air Pollut. Control Assoc.; (United States) Vol. 27:3; ISSN JPCAA
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AEROSOLS
COLLOIDS
DISPERSIONS
ERRORS
FLUIDS
GASES
MANAGEMENT
MEASURING INSTRUMENTS
NOZZLES
PARTICLE SIZE
SAMPLING
SIZE
SOLS
STACK DISPOSAL
WASTE DISPOSAL
WASTE MANAGEMENT