Sensor Research & Development for Implementation with Soil Probing Devices

The traditional site characterization approaches, viz., soil borings and monitoring wells, are labor intensive and costly. Interest has grown rapidly over the past five years in the use of cone penetrometers and other minimally invasive methods to deploy or emplace sensors. The focus of this SBIR proposal is integration of chemical and physical sensors with hydraulically driven probes that can be deployed from vehicles that are smaller and more mobile than cone penetrometers. The Phase I work employs a phased evaluation scheme, culminating in conceptual design development of the most promising candidates. The literature review will be subdivided in terms of the type of information the sensors may provide: chemical, hydrological, and geophysical. Among the sensor strategies that will be investigated are spectroscopic (principally fluorescence and Raman), electromagnetic, force, and chemical reagent types. Preference will be given to sensor technologies that can be applied downhole and provide real-time data. Limited but key experiments to test the durability of sapphire windows and fiber optics as a percussion probe is hammered to depth will be performed. Accelerometers will provide measurement of the forces experienced by the probe during these tests.