Our Portfolio: Characterization Projects

CMST Index | Characterization | SCFA

Fiber Optic/Cone Penetrometer System for Subsurface Heavy Metals Detection

Information
Resources

Technology
Summary Sheet

NETL Product Data Sheet

Innovative Technology
Summary Report

Images

 

Tech ID: 319
Project Overview
The purpose of this project is to develop an integrated fiber optic sensor/cone penetrometer system to analyze the heavy-metals content of the subsurface. This site characterization tool will use the penetrometer to deploy an optical fiber chemical sensor which is based on laser induced breakdown spectroscopy (LIBS).

There are several significant challenges associated with the integration of the LIBS sensor and cone penetrometer. One challenge is to design an effective means of optically accessing the soil via the fiber probe in the penetrometer. A second challenge is to develop the fiber probe system such that the resultant emission signal is adequate for quantitative analysis. These issues will be addressed during this project by investigating both hardware and software solutions.

Technology Description
 In LIBS, a pulse from a high-energy laser, typically a Nd:YAG operating at 1.06 µm, is delivered to the soil sample via an optical fiber. The soil sample will absorb the laser pulse, heat rapidly, reduce to elemental form, and become electronically excited. When the input pulse is removed, the excited electrons drop to lower energy levels with the emission of characteristic photons. The plasma emission is returned from the sample via a second fiber. Elemental analysis is conducted by observation of the wavelength and intensities of the emission lines, which will depend upon the type and amount of material present within the plasma. This technique has shown to be an effective method for the quantitative analysis of contaminants in soils.

Return to Top