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

Accurate measurement of the atmospheric concentration of volatile orga nic compounds is essential when estimating the emission rate from the soil surface or in studies relating to worker exposure to volatile com pounds. For estimating the surface flux, many methods are available wh ich, in general, require profiles of the concentration during the expe rimental period. For example, the aerodynamic and the integrated horiz ontal flux methods require precise determination of the atmospheric co ncentration so that either the concentration gradients or the concentr ation 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 atmos pheric concentration of volatile compounds. Two designs are illustrate d along with a description of their construction and operation. Their use is illustrated with concentration profiles observed in the field.