Electrolytic bath for meter coating - has sec. anode contg. alkaline or ammonium soln. with acid added to electrolyte to compensate for pH rise

摘要

Operation of an electrolytic bath for metal coating a substrate uses a sec. anode cell contg. alkaline or ammonium soln. and sealed with a membrane to allow the passage of alkali or ammonium ions into the soln. Acid is added to the bath to compensate for the pH rise which occurs as hydrogen is evolved at the cathode. ADVANTAGE - Prevents basic components being ppte. at the cathode and chlorine being evolved at the sec. anode which would both act to change the pH of the bath and the content of metal ions in the bath.