Cathodic protection coupons are a simple, size-specific piece of metal with one or more wires attached and are used for evaluating corrosion control or cathodic protection systems protecting a structure, typically a steel pipeline. These measurements include: Native or unprotected structure-to-soil potentials Structure-to-soil potentials with the CP system energized Structure-to-soil potentials with the CP system interrupted To emulate an “Off” structure-to-soil potential without interrupting CP current, typically referred to as a “Coupon Interrupt” reading For magnitude measurements of AC current density on a structure with known induced AC issues Hemi-10 Dual Coupon Details A new design, the "Hemi-10" dual steel C.P. coupon is comprised of 2/each, 10 cm2 half-round coupons designed for maximum contact to earth, which is critically important for AC current density measurements. The dual 10 cm² coupon allows excellent contact to native earth as compared to the smaller 1 cm² coupons. For AC current density measurements, the 10 cm² surface area allows a direct conversion from mA to A/m² without having to use any mathematical conversions.The coupons are mounted inside a durable PVC housing and the Hemi-10 Dual is provided with a three or four lengths of #12 AWG stranded copper cable with RHH/RHW direct burial insulation.
Created by: Pipeline Corrosion Control
Last updated 11/2025