LIF (Laser Induced Fluorescence)

The LIF (Laser Induced Fluorescence) system is used to delineate the depth and horizontal extent of free product and residual petroleum contamination.

The two types of Laser Induced Fluorescence technologies used to investigate petroleum source areas are UVOST® and TarGOST®. Both the UVOST® and TarGOST® are registered trademarks of Dakota Technologies, Inc.

UVOST® (Ultraviolet Optical Screening Tool) is a sophisticated system for detecting residual-phase SVOCs (gasoline, diesel, kerosene, aviation fuel, machine oils, lubricants, and some crude oils), making it a prime tool for investigating petroleum source areas. The principal difference of UVOST® to previous systems is the use of an excimer rather than a solid state laser and the integration of the lasing and detecting systems into a compact, user-friendly package. Use of the excimer and the system integration provides greater reliability, better reproducibility, and less room for operator error.

UVOST® is ideal for locations such as:

  • Service stations where free product is known or suspected
  • LUST (Leaking Underground Storage Tank) sites
  • Refineries and petroleum terminals
  • Most LNAPL (Light Non-Aqueous Phase Liquid) source areas
  • Petroleum DNAPL (Dense Non-Aqueous Phase Liquid) source areas

TarGOST® (Tar-specific Green Optical Screening Tool), is a system that is optimized for refractory petroleum products (coal tars, creosote, heavy crude) and other DNAPLs.

TarGOST® is ideal for locations such as:

  • MGP (Manufactured Gas Plants)
  • Wood treatment facilities
  • Creosote residues

The principal difference between the two systems is the wavelength of the excitation light used. UVOST® uses a laser that emits light in the near-ultraviolet spectrum while TarGOST® uses a laser that emits light in the visible green spectrum.

The Laser Induced Fluorescence includes an integrated EC (Soil Electrical Conductivity) probe to provide indication of general soil characteristics such as sands, clays, and silts. Using the EC logs you can define zones of lower conductivity which allows the movement of contaminants into the subsurface.