The CC-TEV Capacitive Coupler detects TEVs as they pass over the cladding of the high voltage plant. Fast output signals are recorded by the ASM, PrecisePD or PD-SG1 systems. The sensor is encased in a durable PVC sleeve for added protection. Embedded in the body are powerful magnets allowing for coupling to steel enclosures.

Partial discharge activity inside metal clad high voltage plant induces small voltage impulses called Transient Earth Voltages on the surface of the metal cladding. These TEVs travel around the cladding surface to the outside of the gear, where they can be pick up using capacitive coupled transducers.