USEPA Flux Chamber Testing Video
US EPA SURFACE EMISSION ISOLATION FLUX CHAMBER
Surface Emission Isolation Flux Chamber
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).