I have various pieces of equipment that all need to be connected to GND (Chassis GND). The issue I'm having is that I'm connecting an ADC card inside a computer through a metal box with custom electronics that connects into a cryostat (metal shield).
The problem is that if I just use my standard cables then the computer GND is connected to the metal box with the electronics in which is in turn connected to the metal of the cryostat. Now the computer is connected to GND via the plug and the cryostat is connected to GND via a big metal strap to the building GND. This to me smells like a bad case of a ground loop.
So I'm thinking that I need to break the shield somewhere on one of the cables. The questions is where? The electronics are amplifying a rather small signal from the cryostat so I'm guessing that I want to try and keep that shield connection continuous. I was going with breaking the shield at the box on the cable that runs to the computers ADC. Is this a good idea? Should I not worry if the Computer GND and cryostat GND are pretty much connected to the same power strip?
Note that the electronics GND should be floating from the Chassis/building GND.