A tape head writer yoke pole tip and a substrate ground plane are electrically coupled by an electrically conductive wear layer is disposed over the pole tip and the ground plane at the tape bearing surface. A magnetic tape is transported across the tape head and wears away the wear layer. It is identified when a circuit that includes the pole tip, the wear layer, and the ground plane becomes open, and the amount of tape travel until the open circuit occurred is transmitted to a host computer for determination of a tape abrasivity measure as a function of the amount of tape travel. The write element can be used for write operations while the wear layer is present, and after the wear layer has been worn away.
