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-100 Coupon Details
The "Hemi-100" steel C.P. coupon is a 100 cm2 spherical coupon design to improve contact with earth. The larger, sperical shape helps with soil contact upon burial.
The coupon is mounted on a durable PVC housing and the Hemi-100 is provided with a dual length of #12 AWG stranded copper cable with RHH/RHW direct burial insulation, typically green in color.