Essentially wires going across the chassis that control this, that and
> the other thing. So they will be (somewhat) susceptible to magnetic
> field pickup. We want to find out at what level that starts to cause
> issues. Having seen the circuit this will happen well beyond the usual
> EMC field strengths so we can't do that in open air. The Federales would
> swoop in and whisk us away.
Hire some old barn and go to work with alu foil? Nuke proof testing again? ;-)