Probe device for detecting contaminants in subsurface media

摘要

A probe device for in-situ detection of contaminants such as petroleum products in a subsurface media such as soil. The device comprises an elongated probe housing which is driven into the media. An ultraviolet lamp located in the housing provides excitation energy which is reflected through a UV transparent window in the housing to the media by at least one reflecting element in the housing. The reflecting element allows longitudinal offset of the lamp from the window providing space for high intensity UV lamps. A radiation receiver receives fluorescent radiation emitted from contaminants in the media transmitted through the window and provides a signal for analysis equipment on the surface. A concentrating reflector between the lamp and the housing and a focusing lens between the lamp and the reflecting element collect and focus excitation energy from the lamp. A filter between the lamp and the first reflecting element filters unwanted wavelengths from the excitation energy and a filter between the window and radiation receiver filters unwanted wavelengths from the radiation receiver. A calibration receiver is positioned in the optical path to receive excitation energy just before exiting the window. The design improves sensitivity, especially for POL contaminants and eliminates the need for complicated excitation equipment at the surface.