A method and apparatus for producing a photographic silver halide emulsion; a method and apparatus for measuring a silver - or halides union concentration

摘要

A method of producing a silver halide photographic emulsion in which a silver ion concentration in precipitation of a silver halide emulsion in a precipitation bath is controlled, wherein a precipitation bath in which stirring is conducted rapidly and uniformly, and crystal formation and crystal growth are uniformly performed is used, the method comprises the steps of: in a start period of precipitation, quantitavely adding a silver nitrate solution and a halogen salt solution at a constant ratio flow rate; when an EAg value reaches a designated EAg value region in the vicinity of a preset target EAg value, starting a control of an adding rate of the halogen salt solution by using a controller which has an operation period equal to or shorter than 1 sec.; andafter holding a tuning parameter of a proportional, integral and differential (PID) action controller to a minimum response level, conducting a control in which the tuning parameter is switched to an optimum control tuning parameter which corresponds to the preset target value and a solute rate of silver/halogen ions to be added.