Review: This is a report of the testing performed with the second generation probe configuration as reported in [NEK2].
According to the authors:
"A prototype of an integrated steel coupon, salt bridge, and test station assembly was built and tested with the objective to develop a probe that would allow measurements with only negligible or nonexistent voltage drop in soil or water."
Both laboratory and field tests were performed. As in their earlier study [NEK2], the tests were quite limited, but they were able to achieve significant reduction (as much as 92.3% reduction) in voltage drop while reading on potentials. The mos significant reduction in voltage drop was obtained using a large coupon (418 cm2) and a small side sensing(as opposed to a bottom sensing port) port.
Their tests also demonstrated the need to use coupons with exposed areas as large as large holidays on the pipeline to which they are attached.