... of +/- 0.25% + 100 ¼V. A critical DC current density of 1 A/m², which determines if the AC current density limit will be 30 A/m² or 100 A/m², corresponds to a current of 100 ¼A for a 1 cm² AC coupon. The recorded critical voltage across a 10 Ω shunt will be 1 mV...

...Abstract A field study was conducted to determine the influence of the AC current density and of the coating holiday size on the rate of AC corrosion. This field study involved burying steel coupons of three different sizes (i.e., 1 cm², 6 cm², and 10 cm²...

... collected during the site excavations indicated AC current density values near the individual features was significantly greater than reported by the coupon test station as close as 150 feet away. Common industry feedback is that when induced AC potential is less than “a few volts”, generally cited as 2...

... on a bimonthly basis and additional mitigation (in the form of a buried parallel zinc ribbon shield wire) was added on a few selected sections (where the grounding cells alone did not reduce the coupon AC current density below 20 A/m². Coupon B is located approximately four (4) miles downstream...

... structures and cathodic protection requirements needed to mitigate the possible adverse AC current effects. Of a particular interest were the following two issues: (1) the effect of AC current density on the corrosion rate and (2) cathodic polarization requirements necessary to mitigate the impact of AC...