Hemi-10, 10 cm2 Steel Coupons by Farwest Corrosion

Unique Hemispherical Design for Cathodic Protection Testing

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 Coupon

A new design, the "Hemi-10" steel C.P. coupon is a 10 cm2 half-round coupon designed for maximum contact to earth, which is critically important for AC current density measurements.

The 10 cm² coupon allows better 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 coupon is mounted inside a durable PVC housing and the Hemi-10 is provided with a single or dual length of #12 AWG stranded copper cable with RHH/RHW direct burial insulation, typically green in color.

Coupon Ordering Information

  • Specify the Hemi-10 steel coupon
  • Select the number of cable lead wires, 1 or 2, for the coupon
  • Choose a cable length of 25, 50, 75 or 100 feet.
  • Select a cable insulation color (green is the Farwest standard) such as white, blue, orange, etc.











Hemi 10 Single Cable Lead 

Hemi 10 Dual Cable Lead