Mixed metal oxide: an anode of titanium wire, tube, ribbon or mesh coated with a catalytic layer of oxides such as iridium, ruthenium and tantalum. The coating discharges current with very little consumption, so MMO anodes are light, dimensionally stable and long-lived in soil, seawater, fresh water and concrete. They are rated by current density and design life, and once the coating is damaged the bare titanium passivates and stops passing current.
Spec the MMO tubular anodes for the deep well, the old graphite ones only lasted eight years.
Also heard as
- mixed metal oxide
- MMO anode
Related terms
ICCP
Impressed current cathodic protection: CP powered by a rectifier pushing current through long-life anodes.
Groundbed
Group of impressed-current anodes buried in backfill that discharges rectifier current into the earth.
Deep anode
Impressed-current groundbed with anodes stacked in a vertical hole drilled tens of metres deep or more.
Coke breeze
Crushed carbon backfill packed around impressed-current anodes to lower resistance and extend anode life.