Half-cell

nounShop talkCorrosion

Field name for the portable reference electrode that CP techs carry to take potential readings.

What CP techs and coating inspectors call their reference electrode, usually a copper-copper sulfate unit, because electrochemically it is one half of the measuring cell. Techs talk about setting the half-cell in moist soil directly over the pipe, wetting dry ground for contact and keeping it shaded, since poor contact and temperature both skew readings.

Heard on the job

Ground's bone dry, pour a little water on the spot before you set the half-cell down.

Insider tip

Set the half-cell directly over the pipe, not off to the side. A few metres of offset adds IR error and can hide a problem.

Also heard as

  • cell
  • copper cell
  • half cell