SAMPLING MAST FOR MEASURING VOLATILE ORGANIC-COMPOUNDS IN THE NEAR-SURFACE ATMOSPHERE

Accurate measurement of the atmospheric concentration of volatile organic compounds is essential when estimating the emission rate from the soil surface or in studies relating to worker exposure to volatile compounds. For estimating the surface flux, many methods are available which, in general, require profiles of the concentration during the experimental period. For example, the aerodynamic and the integrated horizontal flux methods require precise determination of the atmospheric concentration so that either the concentration gradients or the concentration profiles can be obtained. The accuracy of this information has a direct effect on the accuracy of the flux measurements. The proposed air sampling device provides a suitable method for measuring the atmospheric concentration of volatile compounds. Two designs are illustrated along with a description of their construction and operation. Their use is illustrated with concentration profiles observed in the field.