Four of the electrical feedthroughs (5, 7, 14, 16) are connected to the shields of the BNC contacts. These (HCS, HVS, LVS, and LCS) are connected together (all four) by the Shields bridge switch in the position DOWN. Note, that LVS acts as a shield for LV and ILV terminals, and LCS - for LC and ILC.

The shields bridge provides a current return loop for the current lead shields, as required by some common and advanced impedance spectrometers. Others have it as an option. Many potentiostats have driven shields in which case the shields must be disconnected from each other. In this case, disengage the switch (position UP).

The connector box has additionally two switches other than the shields bridge. Both connect when down. They have the following functions:

Ch+HCS switch: When DOWN this connects the base unit chassis to the shield (HCS) of the high current (HC) terminal. This actively includes the metal block and the connector box in the shielding and guarding between the leads and towards external interference. (Note that if the HC shield is at ground level from the instrumentation, this connection more or less may already exists in some way via the physical suspension of the cell to a rack, etc.). Refer to your measurement instrumentation and chapters in the ProboStat manual for whether to engage the switch or not. We consider the DOWN position to be default and normal.

LC+HCS switch: When DOWN this connects the current terminal LC to the HCS shield. This is practical when you use the LC terminal as a guard electrode and an impedance device, which uses the shield system as a guarding ground terminal. As long as you are not using a guard electrode, the default and normal position of this switch is UP.