METHOD FOR MEASURING CORROSION RATE

• US 3,607,673 A
• Filed: 03/18/1968
• Issued: 09/21/1971
• Est. Priority Date: 03/18/1968
• Status: Expired due to Term

• Current Assignee: Louise S. Moore, Margaret S. Seyl
• Original Assignee: Robert G. Seyl
• Inventors: Seyl, Robert G.
• Primary Examiner(s): Tung, T.
• Application Number:
  US04/713,576
• Time in Patent Office: 1,282 Days
• Field of Search: 204/1.1,195 324/29,30,71C
• US Class Current: 324/425
• CPC Class Codes: G01N 17/02 Electrochemical measuring systems for weathering, corrosion or corrosion-protection measurement
• CPC Class Codes: G01N 27/49 Systems involving the determination of the current at a single specific value, or small range of values, of applied voltage for producing selective measurement of one or more particular ionic species

Abstract

A system for correcting for the IR drop between electrodes when corrosion rate of the electrodes is measured by applying a small DC voltage across the electrodes. Ionic conductor resistance is measured by an AC circuit and the AC circuit is then used to adjust a resistor to an equivalent value whereupon the adjustable resistor is used to add a compensating voltage gain to the voltage applying circuit.

Claims

2. The method of claim 1 wherein said adjustable resistance is connected in series with the DC voltage applying circuit after adjustment of said resistance, said compensating voltage is equal to the IR value of said resistance when so connected, and said adjustable resistance is made ineffective in said voltage delivery circuit after said compensating voltage is added.

3. The method of claim 2 wherein said adjustable resistance is made ineffective by switching it out of said DC voltage applying circuit.

4. The method of claim 2 wherein said adjustable resistance is made ineffective by leaving it in the voltage delivery circuit while balancing the IR value of the resistance with an additional compensating voltage during subsequent polarization voltage measurements.