Time Domain Reflectometry (TDR) Sensor for Detecting Groundwater Contamination

摘要

Groundwater contamination is one of the major problems which is difficult to be detected and avoided. It can take place due to several reasons and may lead to major water related diseases and environmental problems. This paper evaluates time domain reflectometery (TDR) cables as a technology to detect the presence of chemicals and contaminates in sub-surface soil, and to help mitigate ground water contamination. TDR promises to provide an early warning before the contamination takes place and thereby minimize water treatment and remediation expenses. TDR cables operate by detecting changes in the electrical conductivity and dielectric properties of the soil in the surroundings. Under laboratory conditions, TDR cables successfully detected the presence of contaminates in soil, with different levels of saturation to assess its relation to the dielectric constant of a contaminant in the surroundings. For sustainable use of the sensor, heat shrink tubes were used to protect the TDR probe from acids, without adversely impacting the detecting abilities of the equipment. For better economic feasibility of this system, the TDR sensor was made manually, with copper wires soldered and covered with heat shrinking tubes. This manual system acts as a layer over the ground and avoids the problems related to excavation and fixing the sensor under the ground. The system was also able to indicate the location of leaks. It will provide a more precise and accurate system than other leakage detection techniques, so that the operating authority can take the required steps to stop the leakage.