Controlling concentration of developing agent in color developer composition, for use in processing of photo-materials containing silver halides

The developing activity of developer composition is controlled by measuring, using spectrophotometry, the concentration of color developing agent in developer composition. The process of chromogenic development of photo-material containing silver halides, previously exposed, uses a developer composition comprising at least one silver halide chromogenic developing agent A and includes controlling the developing activity of the developer composition by spectrophotometric measuring of its concentration of agent A. Control can be conducted in continuous or periodical regime and preferably produces signal which commands the supply of the new developer composition. An Independent claim is also included for the device for measuring the developing activity of the system of one or more color photographic processing lines, comprising a device for measuring the concentration of chromogenic developing agent A and a device for preselection of the wavelength range at which spectrophotometric analysis is conducted. L'invention concerne un procédé et un dispositif pour contrôler la concentration en agent développateur des révélateurs chromogènes.Le procédé de l'invention comprend la mesure directe par spectrophotométrie de la concentration en développateur chromogène et l'asservissement éventuel du renouvellement du révélateur à cette mesure.Application au renouvellement optimisé des révélateurs chromogènes en cours d'utilisation.