Compressed air prevents damp entering copper cable and thus prevents and worsening of transmission quality. Age and minor damage may lead to leaks in cable. The protective compressed air escapes, damp increasingly worsens transmission quality.
The LANCIER monitoring system locates such faults quickly and precisely - regardless of whether creeping cable faults or sudden breakdowns (e.g. due to earth works) are the cause.
Shorter copper cable lengths are not protected by compressed air. Transmission quality here is monitored via the insulation and loop resistance of the cable concerned and these values are also used to localise faults.