Keyword Definitions; Switching And Inactive Cell Control - Gamry Instruments IMX8 Operator's Manual

Keyword Definitions

The following key terms are used throughout this manual.
Active Cell

The active cell is the cell (if any) currently connected to the system potentiostat. Any electrochemical
measurements are made on the active cell.
Cell

The term cell is used to describe either an electrochemical cell or the switches needed to connect an
electrochemical cell to the system potentiostat.
Channel

An IMX8 contains eight channels. A channel includes cell-switching, a local potentiostat and a D/A
converter. The term cell is used when only the cell-switching portion of a channel is being discussed.
Inactive Cell

The term inactive cell is any cell not currently connected to the system potentiostat. Inactive is a
slightly misleading term since an inactive cell can actually be potentiostated by the IMX8's local
potentiostat on that channel. An inactive cell can be also shorted to mimic an active cell in ZRA mode.
Inactive Mode

Inactive cells can be open, connected to a local potentiostat, or shorted. The term inactive mode
describes this choice of control mode for inactive cells.
Local Potentiostat

A simple low-current potentiostat that maintains potential control on inactive cells. Unlike the system
potentiostat, the local potentiostat is incapable of making electrochemical measurements.
System Computer

The computer responsible for coordinating operation of an IMX8-based electrochemical test system,
not to be confused with the simple micro-controller buried within the IMX8.
System Potentiostat

This is the potentiostat responsible for making electrochemical measurements on the cells used in the
experiment. The system potentiostat is typically a full-featured, computer-controlled instrument.

Switching and Inactive Cell Control

In the Operation Overview, we said you can think of the IMX8 as a complex switch. This section of the manual
describes the IMX8-switching in some detail. In addition, control modes for inactive cells are discussed.
Each of the eight IMX8 channels is made up of an independent set of switches and control circuits. Figure 2-2 is
a simplified schematic diagram for one channel of the IMX8. Switches connected with dotted lines are always
switched together and are therefore treated as one multi-pole switch. All the switches are under control of the
system computer. Shield relays are not shown.
Introduction
15