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Figure 6-1 Front Panel of the EIS Box
The upper (female) connectors are labeled Current Connector. They
carry the cell current between the Counter electrode wires and the
Working electrode wires.
The lower (male) connectors are labeled Sense Connector. They contain
only high-impedance inputs used to sense potentials in the cells.
Gamry's EIS Box standard cell cables always come in pairs. Each cable
has a D-connector on one end, and a number of leads to connect to
electrodes in an electrochemical cell. The D-connector end of the cable is
connected to the appropriate D-Connector on the front of the EIS Box.
The male and female cables cannot be interchanged.
Every EIS Box is shipped with eight pairs of standard shielded cell cables.
The Gamry part number for the Current Cable is 985-00183, and the
Sense Cable is 985-00184. They are both 3 m complex cables, with D
connectors on one end, and color-coded banana plugs on the other end.
Always screw both cell cables into place because cables can fall off the
unit if not properly attached. This can be disastrous if detachment occurs
during an experiment.
Ancillary Apparatus
Do not use the EIS Box with ancillary apparatus connected directly to any
of the cell leads. Examples of ancillary apparatus include DVMs,
oscilloscopes, chart-recorders, and data-loggers. Ammeters and
voltmeters, regardless of their specifications, almost always create
problems when connected to the EIS Box cell leads
Normal Cell Connections
This section assumes that you are using standard, shielded cell cables.
This information does not depend on the length of such cables.
The cell end of the standard cell cables terminates in a number of
banana plugs and pin jacks. Each termination comes with a removable
alligator clip. Table 6-1 identifies the terminals of the cables.
Color
Type
Name
Blue
Banana Plug
Working Sense
Green
Banana Plug
Working Electrode
White
Banana Plug
Reference
Red
Banana Plug
Counter Electrode
Connect both the blue and green cell leads to the positive terminal
(usually). The working electrode is the electrode being tested. The blue
plug connection senses the voltage of the working electrode. The green
working electrode connection carries the cell current. The working
electrode may be as much as 520 mV above the circuitry ground
(floating ground).
Connect the white plug to the negative terminal (usually). The measured
cell potential is the potential difference between the blue and white cell
connectors.
.
Normal Connection
Connect to working electrode
Connect to working electrode
Connect to counter electrode
Connect to counter electrode
Connect the red banana plug to the negative terminal also. The counter-
electrode terminal is the output of the EIS Box's power amplifier.
If your cell is a typical glass laboratory cell, all of the electrodes are
isolated from earth ground. In this case, you may be able to reduce noise
in your data by connecting the EIS Box's Floating Ground to an earth
ground.
Warning: Make sure that your earth-ground connection is
made to a legitimate source of earth ground. Consult a
qualified electrician if you are uncertain how to obtain an
earth ground. Connecting the EIS Box to an incorrect and
unsafe voltage can create a safety hazard
Caution: If any electrode in your cell is at earth ground,
never connect the EIS Box Protective Ground to System
(floating) Ground. Autoclaves, stress apparatus, and field
measurements may involve earth-grounded electrodes.
water pipe can be a suitable earth ground.
Membrane Cell Connections
The EIS Box can be used with membrane cells. In this type of cell, a
membrane separates two electrolyte solutions. Two reference
electrodes are used: one in each electrolyte. Each electrolyte also
contains a counter electrode. The EIS Box controls the potential across
the membrane. Table 6-2 shows the cell connections used with a
membrane type cell.
Color
Type
Name
Blue
Banana Plug
Working Sense
Green
Banana Plug
Working Electrode
White
Banana Plug
Reference
Red
Banana Plug
Counter Electrode
Table 6-2 Cell Cable Connections for a Membrane Cell
Reference electrode #1 and counter electrode #1
must be on one side of the membrane and
reference electrode #2 and counter electrode #2
must be on the other side.
Panel Indicators and Connectors
Front Panel
Power Switch
The Power switch is on the far right side of the EIS Box Front Panel.
Normally the blue Power LED illuminates when the EIS Box is powered
on; see the Power LED description below.
Normal Connection
Connect to reference electrode #1
Connect to counter electrode #1
Connect to reference electrode #2
Connect to counter electrode #2
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