Development of On-Line Analysis System for Components in Plating Bath and Some Chemical Treatment Baths of Electric Galvanizing Process

Abstract

The fundamental approaches for an automatic concentration control system were made of five kinds of chemical treatment baths in an electric galvanizing process. The results obtained are summarized as follows: (1) The concentration of NaOH or Na₄SiO₄ in an alkali-using cleaning bath and H₂SO₄ in a pickling bath can be analized with electric conductivity cell. (2) The concentration of ZnSO₄·7H₂O and H₂SO₄ in an electric galvanizing bath can be automatically analyzed with the combination of specific gravity meter and pH meter. (3) The concentration of (NH₄) ₂CO₃ in an electolytic cleaning bath can be automatically analyzed with electric conductivity cell and those of CrO₃ and its addition in an electrolytic chromate bath can be done with the combination of electric conductivity cell and specific gravity meter.