There are different tests - the best one (IMO) is the bench test, but that requires you to remove the alternator from the vehicle.
There are other tests that will do various charging/discharging/load diagnostics... but if your voltage is spiking that high, that's the sole job of the voltage regulator to keep that in check, which is why I'd suspect that above anything else.
And yes, you're quite right in worrying about other electronics getting damaged - get this fixed before something else gets hurt
You can get a cheap voltage indicator that plugs into your cig adapter. That will give you real time digital voltage display and you can prove it out.