Fig. 3. The solute concentration inferred from the electrical conductivity response of a profiling probe during the advance of a 0.67 g L^-1 KCl tracer step (points) calibrated using the solute pulse numerical integration method of Ward et al. (1994). The calculated breakthrough curve of a nondispersed solute pulse is shown as a solid line. Results are presented as a function of elapsed time since the beginning of application of the tracer step.