EXTENSION OF FAST TRANSIENT TECHNIQUES TO THE NONLINEAR REGION

Problems concerning transients in the non-linear j/eta region are disc ussed. Numerical equations and a program for personal computers to cal culate galvanostatic and modified coulostatic transients in the non-li near region enabled (i) calculation of transients obtained with single and twin working electrode cells, (ii) estimation of the span of over potential (as a function of the kinetic and experimental parameters of the system) to record transients in the linear region, (iii) choice o f cell configuration (single or twin working electrode), (iv) calculat ion of correction factors for errors in j(O) and C-dl, resulting from treatment of transients which moderately exceed the linear region usin g curve fitting to analytical equations which are restricted to the li near region, (v) curve fitting on a PC using numerical expressions. Th e exchange current densities of the Cd2+\Cd(Hg) system were studied us ing the modified coulostatic method in the linear and non-linear regio n. The linear region could be studied only with a twin working electro de configuration. The stoichiometric number was obtained from transien ts considerably exceeding the linear region.