Eliminating BIAS results in Silver Corrosion Ratings from Sulfur in Gasoline.

Sensors in modern automotive fuel systems often use silver or silver alloys, which are susceptible to corrosion from sulfur in gasoline. In the past decade, refiners have shifted to producing lower-sulfur gasoline, but the process requires more severe hydro-treating that destroys naturally occurring compounds that give some protection against sulfur-based corrosion.

Ensuring that fuel stays within acceptable limits requires constant and accurate corrosion testing equipment. Unfortunately, modern silver strip corrosion test methods rely heavily on user bias, as the operator must evaluate corrosivity by interpreting the color and tarnish level of a silver strip after it has been bathed in a fuel sample.

AgDDI corrosion testing equipment, from Ayalytical Instruments (USA), uses a four-step automated vision algorithm and classification process to eliminate user bias. After evaluating the silver strip for corrosivity, the algorithm assigns the sample an integer between 0 and 4, with 0 being no corrosion at all and 4 showing significant blackening. AgDDI provides standardization to the current visual silver strip corrosion test as referred in ASTM D7671 and gasoline fuel specification ASTM D4814.