Soil gas sampling and on-site analysis - using combined probe and drill tubing with internal packer system

摘要

Rapid, interference-free sampling of soil gases and on-site determination of BTX, halocarbons and permanent gases (O2,CH4, CO2 and N2) is carried out by use of a soil gas probe with an internal packer system which prevents gas leakage until measurement and which allows profile measurement over the entire depth in one operation. The on-site analysis equipment includes a photo-ionisation detector for determining gas equilibrium, a capillary gas chromatograph with a miniature thermal conductivity detector, and opt. a computer (e.g. a laptop) for storing the measurement data. ADVANTAGE - The probe cna be combined with an external drill tube in which the internal packer system allows gas entry only to the probe region so that a complete gas profile can be obtained. Interference by air entry on replacing a drill tube by the probe is thus avoided and the drill tube can be left in-situ for permanent gas measurement.