Industrial sites often show heavy contamination of the soil by oil, toxic and persistent organic compounds. One way to decontaminate these areas is the use of radio frequency heating for soil remediation. This RF treatment technology is a technique where the soil is heated to increase volatility or reduce viscosity of organic contaminants by measuring the temperature through a fiber optic temperature sensor / thermometer. A high- power generator will deliver energy in radio frequency range. The polluted soil is covered with electrodes, which will heat the surface dielectric. Besides, several fiber optical probes are put in the soil. Depending on the measured value different values of temperature and temperature distribution can be realized in the soil. Depending on the level of contamination the temperature will be increased slightly to activate a higher decomposition of soil organisms, alternatively the soil water will condensate in a temperature range up to 150° Celsius together with non-steam resistant organic contaminations. A perforated soil air extraction system takes the steams away and recirculates them into a filter system.
The outer jacket of the fiber optic temperature sensors is made out of teflon, at the sensor tip a GaAs-crystal (gallium arsenide) is attached. The probe sensor is completely non-conductive. Optocon’s fiber optic sensors offer complete immunity to RF and microwave radiation with high temperature operating capability, intrinsic safety, and non-invasive use. The probes are also designed to withstand harsh and corrosive environments.