LOUIS RAMALEY and WEE TEE TAN. Can. J. Chem. 59, 3326 (1981) The theory of square wave voltammetry for reversible electrode reactions is expanded to include average currents and currents flowing to a growing drop (single drop square wave polarography) using an expanding plane model. Excellent agreement between theory and experiment was found for the reduction of Fe(III), good agreement for the reduction of Cd(I1). The expanding plane model proved superior, but not greatly superior to the simpler theory. For the case of average current the effect on the polarogram of the times at which integration is started and stopped is discussed. Integration decreases sensitivity but increases signal-to-noise ratio. The conditions for maximum analytical usefulness are presented.LOUIS RAMALEY et WEE TEE TAN. Can. . I . Chem. 59. 3326 (1981) En utilisant un modele plan elargi. on a developpe la theorie de la voltametrie en signaux carrCs pour des reactions reversibles d'electrode dans le but d'inclure les courants moyens et les courants circulants dans une goutte en formation (polarographie en signaux carres d'une goutte unique). L'accord est excellent entre la theorie et I'experience dans le cas de la riduction de Fe(II1) et il est bon dans le cas de la reduction de Cd(I1). L e modele plan elargi se revele superieur, mais il ne surpasse pas la theorie la plus simple. On discute de I'effet. du temps de depart et d'arret de I'integration. sur le polarogramme dans le cas du courant moyen. L'integration diminue la sensibilite mais augmente le rapport signallbruit. On propose des conditions qui conferent a ce modele une grande utilite du point de vue analytique.[Traduit par le journal] Introduction Traditionally, pulse and square wave polarography have been techniques in which the current is sampled a t only one potential on each mercury drop. Construction of the entire polarograni thus requires several hundred drops. Even with very short drop times, such analyses are quite lengthy. Superimposition of a square wave on a potential sweep and application of the result to a stationary electrode has been used to reduce analysis time considerably (1, 2).