PH sensitive reference electrode in electrolytic desilvering

US6299754A · kind A · utility

Assignee

• Agfa-Gevaert NV · BE

Inventors

• Patrick Mertens · Vrasene, BE
• Benny Jansen · Geel, BE
• Werner Van De Wynckel · Mortsel, BE
• Frank Michiels · Arendonk, BE

Key dates

• Filing date: May 22, 1996
• Grant date: Oct 9, 2001
• Expiry date: May 22, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C25C1/20
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

An apparatus is disclosed for electrolytic desilvering of photographic processing solutions, more particularly fixing solutions or bleach-fixing solutions, comprising an electrolysis unit equiped with a monitoring system comprising a cathode, an anode and a reference electrode, characterized in that said reference electrode is a pH sensitive electrode. The desilvering is preferably performed under potentiostatic conditions. Whe using a pH sensitive reference electrode the cathodic plating potential is automatically corrected for pH changes. A preferred pH sensitive electrode is a glass electrode.