Patent ID: 7282928
Filing Date: 2007-10-16
Classification: G01N,G01R

Abstract:
1. A loop-powered corrosion measurement device for measuring or monitoring corrosion of a structure exposed to an electrolyte, comprising: a loop interface coupleable to a 4-20 mA loop and comprising a power system to power the device using power from the 4-20 mA loop; a probe interface system with signal conditioning circuitry to interface with a plurality of measurement electrodes situated in the electrolyte, the signal conditioning circuitry comprising: excitation circuitry operative to provide sinusoidal excitation signals to the electrolyte via a first one of the electrodes, and sensing circuitry operative to sense one or more electrical current signals related to corrosion via at least a second one of the electrodes; and a processing system operatively coupled with the probe interface system to control the excitation signals provided to the electrolyte and to compute at least one corrosion related value based on more than one cycle of a sinusoidal current signal sensed by the sensing circuitry using harmonic distortion analysis.