3.3.5 Miniature resistivity probe

Coupled heat and contaminant transport in ground water are very important issues in environmental engineering, which are related to

+ storage and disposal of heat-generating radioactive wastes,

+ high-temperature discharges from power plants and industrial processing plants,

+ underground explosions heat,

+ waste dissipation from underground pipelines,

+ transport processes occurring in geothermal reservoirs,

+ and thermal storage aquifers.

Therefore, much of the work involving the centrifuge modelling of contaminant transport, has concerned on the migration of an ionic pollutant through saturated deposits of soil to date, several types of miniature resistivity probe have been developed for use in centrifuge modelling, together with several models of electrical driver for probe energisation.

The presented miniature resistivity probe is manufactured to investigate coupled heat and contaminant transport in the soil surrounding a buried waste source. During each test, temperature and concentration changes in the soil surrounding the pipe were monitored by miniature combined resistivity and temperature probes. The miniature probes, which were specifically designed for the work, comprised two Pt-Rb wires buried in a small cylindrical core of porous ceramic material. Temperatures at the electrodes were measured by nickel-chrome thermocouples, which were bonded to the base of the probes. The probes were calibrated for a range of temperatures from 18 to 60 oC and a range of contaminant mass fractions from 0 to 11.7x10^-3.

Hensley, P.J., and Savvidou, C. (1993) : Modelling coupled heat and contaminant transport in ground water, Int. J. Numerical Anal. Methods Geomech., 17, pp. 493-527.