Common ground for electronic lapping guides

A system, comprising:

• a substrate comprising a plurality of read heads, each read head comprising:
• a read sensor configured to sense data stored in a magnetic media,
• an ELG configured to indicate, based on a resistance of the ELG, a stripe height of the read sensor, wherein the ELG is electrically coupled to the substrate, and
• a bonding pad electrically coupled to the ELG, wherein the bonding pad, the ELG, and the substrate are part of a current path permitting current to flow through the ELG,
• a lapping unit configured to simultaneously lap an air bearing surface on the plurality of read heads, wherein the substrate is mounted on the lapping unit;
• and
• a lapping controller electrically coupled to the bonding pad and the substrate, the lapping controller configured to measure the resistance of the ELG using the current path and transmit instructions to the lapping unit based on the measured resistance.

A method, comprising:

• attaching a first wire to a bonding pad on a first one of a plurality of read heads disposed on a substrate, the first read head comprising:
• a read sensor configured to detect magnetic orientation changes in a magnetic media, and
• an ELG configured to indicate, based on a resistance of the ELG, a stripe height of the read sensor, wherein the ELG is electrically coupled to the substrate, and wherein the bonding pad is electrically coupled to the ELG;
• attaching a second wire to a substrate access pad electrically coupled to the substrate;
• and
• applying a voltage potential across the first and second wires such that current flows through the substrate and the ELG.