Each analog input has the following structure in order to reduce external noise influence:
Each input can be grounded or kept floating in order to be able to reject ground loop noise due to sensors cabling. A resettable fuse is used and can support, if grounded, up to 30V in case of ground potential difference (to avoid) between sensors and analyzer. Each input structure is mainly designed as symmetric in order to provide high common mode voltage rejection.
Analog ground is connected to the analyzer frame. Inside the analyzer the cabling is separated between analog parts and digital parts in order to keep high signal/noise ratio.
Ethernet connection is designed and tested to be floating from the frame (Ethernet cable connection is done using an isolation transformer). So ground loops can be avoided between analyzer and PC (be careful using shielded Ethernet cable, STP, as generally shield is connected to each connector frame).