How do you isolate weigh-bridge systems from lightning strikes?

It is impossible to isolate weigh-bridge systems from lightning strikes as it impossible to separate them from the ground. It is possible to mitigate any damage by understanding what is happening when a surge or transient enters your scale system. It is looking for the best source to ground. Your scale weigh-bridge is just in the way to ground or is the ground. The load cells, circuitry of the summing and the digital indicator are simply by-standers. Collateral damage so to speak. Usually transients come in the electrical transmission lines. If you have a single point ground located at the scale foundation you can run a large gage wire from that ground rod to the ground rod located at your power supply breaker box. The makes the ground common and gives any transients a path that has less resistance bypassing your scale compnents.Phone lines also carry a ground and can enter through the DSL or modem (same for cable modems). Identify those grounds and also make those common.This eliminates 99% of all transient surges and doesn't cost the end user a great deal of money to take precautions. I sincerely hopes this helps you.