Method of calibrating conductive metal oxide electrodes

• US 4,551,209 A
• Filed: 01/19/1984
• Issued: 11/05/1985
• Est. Priority Date: 01/19/1984
• Status: Expired due to Term

• Current Assignee: Integrated Ionics Incorporated
• Original Assignee: Integrated Ionics Incorporated
• Inventors: Lauks, Imants R.
• Primary Examiner(s): Metz, Andrew H.
• Assistant Examiner(s): Nguyen, Nam X.
• Application Number:
  US06/572,200
• Time in Patent Office: 656 Days
• Field of Search: 204/1 T, 204/401, 73/1 G, 73/1 R, 204/402
• US Class Current: 205/790.5
• CPC Class Codes: G01N 27/4165 for pH meters

Abstract

A conductive metal oxide electrode can be calibrated by immersing the electrode and a reference electrode in a solution of known pH and applying to them a setting potential which is approximately equal to the steady state potential that would be observed for that electrode with respect to the reference electrode in a solution of that value of pH.

Claims

1. A method for calibrating conductive metal oxide electrodes wherein the oxide is an oxide of a metal selected from the group consisting of platinum and rhenium group metals comprising the steps of:

immersing said metal oxide electrode into a solution of known pH;

immersing a reference electrode into said solution, and

applying across said metal oxide electrode and said reference electrode a potential equal to approximately the steady state potential that is observed for a second electrode having substantially the same chemical composition as said metal oxide electrode when said second second electrode is immersed in a solution of the same pH and is allowed to stabliize slowly in open circuit conditions.

2. The method of claim 1 wherein said metal oxide electrode is an iridium oxide electrode.