Use of a cone penetrometer deployed video-imaging system for in situ detection of NAPLs is subsurface soil environments

摘要

A new technique for real-time, in situ, microscopic detection of Non-Aqueous Phase Liquid (NAPL) in subsurface soil environments is described. The method uses a SSC San Diego developed video imaging system (Geo VIS) that is integrated into a cone penetrometer probe. Soil in contact with the probe is imaged through a sapphire window and lens system with a miniature CCD color camera as the probe is pushed into the ground. The soil is illuminated with an array of white light emitting diodes located in the rpobe. The video signal fromt he camera is returned to the surface where it is displayed in real-time on a video monitor, recorded on a video cassette recorder (VCR), and/or captured digitally with a frame grabber installed in a mcrocomputer system. In its current configuration, the system images an area that is 2x2.5 mm which provides a magnification factor of approximately 100x when viewed on a standard 13-inch monitor.