Beyond the Basics: Contamination Detection and Other Applications of CPT Equipment
Cone Penetration Testing equipment was originally designed – and is still most commonly used – to characterize subsurface soil behavior types. But when you invest in CPT equipment, you are getting the capability to do much more. A variety of sensors and in-situ samplers can be integrated into CPT modules, making CPT equipment a versatile and efficient choice for contamination detection, environmental site assessment, and other field applications. CPT equipment has several advantages over conventional hollow stem auger drilling and percussion drilling based methods, especially in contaminated soils. Specialized CPT tests can identify contaminants and determine the physical extent of the contamination with minimal disturbance of the soil, thus avoiding costly disposal of drill cuttings and minimizing contact between field personnel and potentially hazardous materials. Here’s an overview of some tests and technologies that you can harness via CPT equipment: Temperature: Temperature data is obviously useful in locating zones of different ground temperature, for example frozen soil. However, it can also help to identify soil contaminants that generate heat due to chemical or biological activity. Electrical Resistivity: The electrical properties of soil are changed when the soil is contaminated. For example, soils containing non-aqueous-phase (NAPL) compounds exhibit higher resistivity than normal, while soils containing dissolved organic compounds such as can be found in landfill leachates have significantly lower resistivity. Fluorescence Detection: Most hydrocarbons produce fluorescence when irradiated with certain kinds of light. Thus, hydrocarbon contamination can be efficiently detected by integrating LEDs of a particular wavelength (or sometimes lasers) into CPT cone modules. The detected wavelength of the fluorescent response to the excitation source is graphed in real time and is used to determine the areas of interest and further define contaminants. The integrated camera or video camera module can also be used to visually inspect in-situ characteristics such as [...]