Gamry Instruments EIS Box, Operator'S Manual, Page: 19 / 52

General Operation
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The
system computer also controls the instrument . When a cell is connected to the instrument cell leads, the
computer causes a test to be run on that cell. The test can be as simple as a single current or potential
measurement or as complex as a cyclic scan. The computer software and
instrument are responsible for taking
the measurement and storing it.
The EIS Box
instrument in Figure 3- 1 is shown as a “black box”. The relays in the EIS Box can carry currents up
to 5 A.
In a typical EIS Box experiment, the
system computer cycles through the cells. Each cell is connected in turn to
the instrument and used to collect a measurement. Usually the computer delays at the end of each cycle
through the cells so that the measurements on each cell are separated by a fixed time period.
Keyword Definitions
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 instrument.
Channel
An EIS Box contains eight channels. A channel includes cell-switching relays. 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 instrument.
Instrument
This is the instrument responsible for making electrochemical measurements on the cells used in the
experiment. The instrument is typically an EIS Box.
System Computer
The computer responsible for coordinating operation of an EIS Box-based electrochemical test system,
not to be confused with the very simple micro-controller buried within the EIS Box.
Switching and Inactive Cell Control
In the Operation Overview, we said you can think of the EIS Box as a complex switch with controller. Each of
the eight EIS Box channels is made up of an independent set of switches and control circuits. All the switches
are under control of the system computer. The system computer must insure that only one cell at a time is
connected to the instrument, therefore a main switch controls which cell is active.
Communications Overview
The system computer communicates with the EIS Box via an ethernet connection or a USB cable.
Switching from channel to channel involves electromechanical relays. You will hear a click
each time relays activate during the switching process.