Patent ID: 9188562
Filing Date: 2015-11-17
Classification: G01N

Abstract:
1. A method of determining the content percentage of silver within a specimen containing silver, comprising the steps of: providing a testing apparatus having a microprocessor, a source of electrical current, and an electrical circuit including a pen probe having a supply of a corrosive electrolyte, said electrical circuit having a fixed resistance circuit path and a variable resistance circuit path; depositing said electrolyte from said pen probe onto said specimen to create a growing electrically resistive layer between the pen probe and the specimen, said electrically resistive layer having a rate of growth; measuring a flow of electrical current through at least one of said circuit paths as said electrically resistive layer accumulates; ascertaining a rate of change in said flow of electrical current through at least one of said circuit paths; and utilizing the rate of change in said flow of electrical current through said variable resistance circuit path to define the content percentage of silver within said specimen, the rate of growth of said electrically resistive layer being proportional to the content percentage of silver within said specimen, said growing electrically resistive layer decreasing the flow of electrical current through said variable resistance circuit path which contains said specimen.