luminescence arising in the recombination of ion-radicals formed in the course of the electrolysis of a solution of an activator, such as isobenzofuran and isoindole, in an accompanying electrolyte, such as dimethyl formamide (seeLUMINESCENCE); the excited molecules of the activator formed as a result of the recombination of their ion-radicals are converted to the ground state, emitting light quanta. Electro-chemiluminescence may be used in indicator instruments: upon excitation of a luminophor by a changing electric field, the luminescence is concentrated near the electrode, and, by using electrodes with special shapes, flashing numbers and letters may be constructed. (See and CHEMILUMINES-CENCE.)