Gamry Instruments Reference 30k Booster, Руководство оператора

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Introduction – Grounding (Earthing)
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Grounding (Earthing)
A Reference 30k Booster system can be operated floating (isolated) from earth ground. This allows control
current or voltage on electrochemical systems where one electrode or the system plumbing is earth-grounded.
System grounding is discussed more fully in Appendix B. See this chapter if you need to float your cell.
Operating Modes
As described above, the Reference 30k Booster can be thought of as an additional current range added to the
Reference 3000 instrument. This additional range is available in all three common Reference 3000 control
modes: potentiostatic, galvanostatic and ZRA.
Potentiostatic: In this mode, the system controls the potential between two voltage-sensing points. Some of
Gamry’s control software allows variation in potentiostat mode, including 2-electrode and 3-
electrode operation, and connection of a high-voltage electrometer.
Voltage-sensing is always done using the leads in the Reference 3000’s sense cable. In the
standard or “low-voltage” mode, the voltage is always measured between the Reference
(white) lead and the Working Sense (blue) lead. In high-voltage mode, the sensing is done
between the Counter Sense (orange) lead and the Working Sense (blue) lead.
Galvanostatic: In this mode, the system controls the current flow through the cell. The current can be
measured directly by one of the Reference 3000’s current ranges or can be measured on the
Reference 30k Booster’s 30A range. In either case, the current flows between the high-
current terminals on the front panel of the Reference 30k Booster.
ZRA: In this mode, the cell is kept with zero volts between the counter sense (orange) lead and the
working sense (blue) leads.
Operation with Gamry Instruments Software
Gamry’s Framework software was written to allow device-independent potentiostat operation. Most tests can
run using any Gamry Instruments potentiostat. There is one obvious limitation: tests cannot exceed the
specifications of the potentiostat in the system.
Some Potentiostatic mode scripts in Framework software normally only allow current-range auto-ranging; they
do not allow user-selection of a current range. All Gamry DC Corrosion Scripts operate in this way. A special
provision in the Reference 30k Booster driver allows limited operation of these scripts. Whenever the scripts
attempt to set up current-range auto-ranging, a dialog box appears that allows you to enter a maximum
expected current. A typical dialog box is shown in Figure 2-2.
Figure 2-2
Simplified Range Switching Reference 30k Booster
After you click the OK button, the entered current is used to set a current range in either boosted or pass-
through mode. The range is not changed during curve acquisition.
One place that auto-ranging is allowed is during acquisition of an EIS spectrum. The system turns off the cell,
changes the current range, and then turns the cell back on when EIS needs a change in the current range.