Field Demonstration of tbe SCAPS XRF Metals Sensor

The SCAPS XRF Metals Sensor adds metals detection capability to the DOD Site Characterization Penetrometer System (SCAPS). It works using X-ray Fluorescence (XRF) to detect-all metals above calcium in the subsurface soil. The sensor head contains a miniature x-ray tube and cooled solid-state detector to achieve performance comparable to laboratory units in a down-hole sensor. The sensor may be pushed to depths as far as 150 feet by the cone penetrometer system and is designed to detect metals at concentrations below 100 ppm in all soil types regardless of moisture level. The system has been tested on the bench and demonstrated at a site. Following a brief overview of the sensor design and operation, the results of the bench testing, including evaluation of detection limits for a list of common contaminant metals, will be presented. Some operational test results are included, both on techmcal%performance of the sensor and its robustness and effectiveness as a field tool. Finally, a list of potential improvements is given. Prepared in collaboration with SFA, Inc., Upper Marlboro, MD and University of Toledo, Toledo, OH.