Abstract: A system for monitoring corrosion in metal by comparing a test sample exposed to a corrosion causing environment and a reference sample exposed to a protected environment. An AC voltage source generates a square wave signal oscillating between ground and voltage Vcc and a filter is positioned to filter the signal to produce a sine wave with no second harmonic component. A voltage-driven current source and inverting amplifier produce a current referenced to 0.5 Vcc to provide an AC current from the drive voltage driven sinusoidally and symmetrically above and below 0.5 Vcc. A transformer steps up the AC current and thereafter transmits the current through the samples to an amplifier for amplifying the current to provide outputs in a ratio representing the degree of corrosion of the reference sample. The system can operate in situ for on site measurement and uses relatively low current to permit long operation.

Abstract: A system for scheduling maintenance on equipment includes a metallic element placed on or near a piece of equipment in an environment, a measuring and data storing device configured to measure the resistance of the metallic element, and a computer configured to determine the amount of corrosion experienced by the metallic element based on the resistance measured by the measuring and data storing device and to correlate the amount of corrosion with a maintenance schedule for the piece of equipment. A method for scheduling maintenance on a piece of equipment is also described. The method includes placing a metallic element on or near the piece of equipment, determining the amount of corrosion experienced by the metallic element, and correlating the amount of corrosion with a maintenance schedule for the piece of equipment.