Integration of a SAW Sensor System into Penetration Cones for In-Situ Soil Gas Analysis

In this work we present the first integration of a SAW sensor based sensor system (electronic nose) into a percussion driven penetration cone for in situ soil gas analysis. The new system includes an 8-fold SAW sensor array with different polymers as sensitive coatings, a sampling system with absorbent materials for enrichment of the analyte and de-richment of water vapour, an inlet system to probe the ambient soil, a rechargeable battery pack and finally a remote control via Bluetooth interface to an external PC on the ground. By means of an integrated spring based mechanical decoupling system measurements with the sensor array could be performed even during penetration of the cone via a pneumatic hammer. Proper operation of the sensor system could be performed until the penetration cone has reached a depth into the soil of 8m. Various measured soil gas profiles of contaminated test sites with penetrated depth as parameter can be shown.