A comparison of concentration measurement techniques for the estimation ofthe apparent mass diffusion coefficient

In this article we compare two different techniques to measure the concentr ation of saline solutions for the identification of the apparent mass diffu sion coefficient in soils saturated with distilled water. They are the radi ation measurement technique and the electrical conductivity measurement tec hnique. These techniques are compared in terms of measured quantities, sens itivity coefficients with respect to unknown parameters and the determinant of the information matrix. The apparent mass diffusion coefficient is esti mated by utilizing simulated measurements containing random errors. The Lev enberg-Marquardt method of minimization of the least-squares norm is used a s the parameter estimation procedure. The effects of the volume of saline s olution injected into the column devised for the experiments on the accurac y of the estimated parameters are also addressed in this article.