The authors have developed a Cone Penetration Testing (CPT) probe that allows continuous collection of soil gas from the vadose zone during penetration. Concentrations of volatile organic compounds (VOCs) in the sampled ags are enhanced by ehating the soil in situ to promote thermal desorption, thereby providing more accurate assessment of the in situ concentration in teh matrix than gas sampling at ambient temperature. The sampled soil gas, after heating, can be directed through downhole sorbent traps or can be transferred directly to an analytical instrument at the surface. A heated transfer line prevents VOCs and water vapor from condensing during transfer. The new probe allows continuous sample collection without interrupting CPT production to retrieve soil samples. It offers the further advantage of eliminating losses of VOCs due to the handling of soil samples. The probe and sorbent trap module can be used alone or in conjunction with a variety of CPT-based sensors.
展开▼
