Corrosion ratemeter

Abstract

Abstract A CORROSION RATEMETER WITH TEST (SPECIMEN), REFERENCE AND THIRD ELECTRODES CONTACTABLE BY A CORRODENT. AN INPUT CIRCUIT CONNECTS THE TEST AND REFERENCE ELECTRODES TO AN ISOLATION AMPLIFIER. THE AMPLIFIER PROVIDES IN ITS OUTPUT CIRCUIT AN OUTPUT CURRENT SIGNAL REPRESENTATIVE OF THE POTENTIAL DIFFERENCE BETWEEN THE TEST AND REFERENCE ELECTRODES. A CAPACITANCE MEANS IN SERIES WITH THE INPUT CIRCUIT IS CHARGED TO THE FREELY CORRODING POTENTIAL REPRESENTATIVE OF THE POTENTIAL DIFFERENCE BETWEEN THE TEST AND REFERENCE ELECTRODES DURING "NULL" OPERATION. AS A RESULT, THE INPUT CIRCUIT APPLIES A ZERO POTENTIAL INPUT SIGNAL TO THE ISOLATION AMPLIFIER. A REFERENCE VOLTAGE SIGNAL IS APPLIED TO THE INPUT CIRCUIT OF THE AMPLIFIER DURING "OPERATHE AMPLIFIER NOW PROVIDES, IN ITS OUTPUT CIRCUIT BETWEEN THE THIRD AND TEST ELECTRODES, AN OUTPUT CURRENT SIGNAL OF SUFFICIENT MAGNITUDE THAT THE TEST ELECTRODE IS POLARIZED BY A CERTAIN POLARIZATION POTENTIAL (E.G., 10 MILLIVOLTS). READOUT MEANS CONNECTED TO THE ISOLATION AMPLIFIER MEASURE THE OUTPUT CURRENT SIGNAL REPRESENTATIVE OF THIS POLARIZATION POTENTIAL, WHICH OUTPUT CURRENT SIGNAL IS REPRESENTATIVE OF THE CORROSION RATE OCCURING AT THE TEST ELECTRODE. VOLTAGE LIMITER MEANS CAN PROVIDE THE REFERENCE VOLTAGE SIGNAL TO CONTROL THE RATE OF CHANGE AND MAGNITUDE OF THE OUTPUT CURRENT SIGNAL.

Inventors

• 👤 H Wilson

Bibliographic Details