METHOD AND APPARATUS FOR MONITORING CORROSION AND REPORTING SAME ACCORDING TO ACCEPTED INDUSTRY STANDARDS

摘要

A method and apparatus for using a coated piezoelectric crystal tomonitor and report corrosion in terms recognized as conforming to an industrystandard is disclosed. The present invention provides a method of and systemfor monitoring corrosion in a corrosive atmosphere, comprising and carryingout the steps of exciting in the atmosphere a crystal, coated with a corrodiblemetallic substance and having a known vibration frequency; measuring thechange in the frequency of vibration resulting from corrosion of the corrodiblesubstance during each of a plurality of intervals of time, including a referenceinterval and at least one subsequent measurement interval; generating athickness signal representing the thickness of corrosion corresponding to themeasured change in frequency during the measurement interval and convertingthe corrosion thickness signal for the measurement interval to a reference signalrepresenting the thickness of corrosion accumulated during the referenceinterval. The invention also preferably includes correcting the measuredfrequency change during each interval to account for any deviation in thetemperature in the atmosphere from a preset standard temperature. The presentinvention also preferably includes a humidity sensor, which serves as theimpetus for providing an alarm to the user if the relative humidity is above apreset limit, or if the relative humidity changes during an interval by more thana preset limit. A corrosion monitor according to the present invention findsapplication in such environments as industrial process measurement and controlrooms, motor control centers, electrical rooms, semiconductor clean rooms,electronic fabrication sites, commercial data centers, museums, libraries, andarchival storage rooms.