Rohrback Corporation

Rex V Rhoades

Charles M Finley

James L Geer

An electrical resistance-type corrosion measuring probe provides an output signal corrected for temperature by computing the ratio of resistance of a test element exposed to a corrosive element to resistance of a reference element protected from the environment. A secondary temperature compensation is provided for by compensating the corrosion output signal for dynamic or short term variation of temperature difference between test and reference elements. The corrosion output signal is compensated for still other environmentally induced errors by measuring temperature gradient between an inner end of the probe within the fluid environment and a portion of the probe outside the corrosive fluid environment. Errors in corrosion probe output signal due to bending stresses on the probe that result from fluid flow velocity and fluid pressure of the environment, are also compensated by measuring bending strain and pressure to provide additional compensation for the corrosion output signal.

Corrosion measurement with multiple compensation

An electrical resistance type corrosion measuring probe has a test element exposed to a corrosive environment and an adjacent reference element protected from the environment. Electrical circuitry is connected to the elements for measurement of resistance ratio. This provides a corrosion output signal having a first order of temperature correction provided by the reference element. Secondary temperature compensation for dynamic or short term variation of temperature of the corrosive environment is provided by thermocouple measurement of temperatures of the test and reference elements and compensating the corrosion signal in accordance with the directly measured short term temperature difference of the elements.

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Anaheim, CA, United States of America

Rex V Rhoades