Determination of soil porosity by a simple and novel technique of fusing thoron diffusion experiment and modeling

In this study, the thoron diffusion characteristic in soil is used as a tool to measure the porosity of the soil. The feasibility is demonstrated by a simple and compact experimental set up. The soil matrix, whose porosity is to be measured, is placed between the thoron source on side and an air chamber connected to thoron monitor on the other end. The methodology is based on reproducing the experimental results by theoretical modeling involving fixing of the input thoron diffusion coefficient by repeated trials. The porosity is estimated by using the empirical relation involving porosity and thoron diffusion coefficient in soil. The values are compared with porosity estimations through true density (particle density) measurements with pycnometer. A good agreement is observed between both the measurements techniques and the relative error is found to be within 10%. (author)