Gamry ECM8, Operator'S Manual

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Appendix C -- I/O Connections for the ECM8--Normal Cell Cable Connections
4 - 6
Normal Cell Cable Connections
Normally you can use one of Gamry Instruments' standard cell cables to connect each channel's connector
to its cell. Gamry supplies cables that are 1.5 m, 4.5 m or 9 m in length. Special purpose cables are also
available.
The standard cell cable terminates in banana plugs and one pin jack. Table C-2 identifies each terminal of
the cable and its connections to the cell. This table can be used for PCI4 all connections regardless of
operating mode.
Table C-2
Normal Cell Cable Terminations
Color Type Name Normal Connection
Blue Banana Plug Working Sense Connect to working electrode
Green Banana Plug Working Electrode Connect to working electrode
White Pin Jack Reference Sense Connect to reference electrode
Red Banana Plug Counter Electrode Connect to counter electrode
Orange Banana Plug Counter Sense Connect to counter electrode
Long Black Banana Plug Floating Ground Leave open or connect to a Faraday shield
Short Black Banana Plug Chassis (Earth) Ground Leave open or connect to a Faraday shield
The working electrode is the specimen being tested. You make two connections to the working electrode.
One of the two connections, with the blue banana plug, is used to sense the voltage at the working
electrode when you use the ECM8 with a system potentiostat that includes a differential electrometer. If
you are using a system potentiostat with a single ended electrometer, you can leave this wire disconnected.
The green working electrode connection carries the cell current.
Connect the white pin jack to the cell's reference electrode, generally an SCE or Ag/AgCl reference
electrode. Connect the red (and orange) banana plug to the counter or auxiliary electrode.
The longer black lead is connected to the system potentiostat's ground. The shorter black lead is connected
to earth ground. In most cases, these terminals should be left disconnected at the cell end. When you do
so, take care that they do not touch any of the other cell connections.
When you are measuring very small currents, you may find that a metal enclosure completely surrounding
your cell (a Faraday shield) will significantly lower the current noise due to AC pickup at the cell. This
Faraday shield should generally be connected to both black cell leads.
You can add an alligator clip (provided) to each of the cell connection. The alligator clips simply slide onto
the banana plugs. If you need to permanently change the terminations on your cell cable feel free to
remove the existing terminations and replace them with your desired termination.
In a few cases, you may find that you need to modify the cell cable or make a special purpose cable. By far
the easiest changes involve modifying a standard cell cable. If you do decide to make your own cables, we
recommend that you use coax cable for all the cell connections. Connect the shield of the coax to the pin
recommended in Table C-1 on the PCI4 end, and leave the shield open on the cell end.
Cell cables longer than 3 meters may result in degraded instrument performance. Increased noise and
decreased stability both can occur. However, with most cells, the instrument will work acceptably with an
extended cell cable, so our advice is go ahead and try it.