The surface emissions isolation flux chamber is one of the most promising
technologies for the direct measurement of VOC emissions. Guidelines have
been developed by the EPA for application of this methodology to land surface
(Radian, 1988). The technology is also applicable to liquid surfaces (Eklund
et al, 1985; Eklund et al, 1987). The technology uses a chamber to isolate
a known surface area for emissions measurement. Clean, dry sweep air is
added to the chamber at a metered rate. Within the chamber, the sweep air
is mixed with emitted vapors and gases by the physical design of the sweep
air inlet and/or an impeller. The concentration of the exhaust gas is measured
at the chamber outlet for specific VOCs by real-time instruments and/or
is usually collected as a sample for laboratory analysis. The emission
flux can be calculated as:
Ei = CiQ / A
where Ei = emission rate of component i (ug/m2,min); Ci =
concentration of component i (ug/m3); Q =
sweep air flow rate into chamber (m3/min); and A =
surface area enclosed by chamber (m2).
CE Schmidt, Ph.D
Environmental Consultant
19200 Live Oak Road, Red Bluff, California 96080
PHONE: (530) 529-4256 FAX: (530) 529-4878
Please call today, or send an email to SCHMIDTCE@aol.com