Tension fence

Tension detection is mechanical. A wire under constant load is connected to a strain module; climbing, lifting or cutting changes that load. Because the fence itself carries no voltage, tension is preferred around fuel storage, public footpaths and sites where an electric fence would trigger objections or additional permits.

The trade-off is that tension needs a mechanically sound fence line. Loose posts, long unsupported spans and trees pushing on the wires create slow drifts that are harder to separate from a real climb. The installation must be tight and the posts must be stable before the electronics are tuned.

Start from the middle of the adjustable range, then test three events: a firm pull at mid-span, a cut on the farthest wire, and a normal wind gust. Raise the threshold until wind and thermal movement no longer alarm, then lower it one step and repeat the pull test. Record the final value on the as-built drawing so the next technician does not restart from zero.

For dual-zone hosts, set and test each zone independently. A shared threshold often hides a weak zone behind a stiff one, especially when one run is short and the other is exposed to wind.