eDAQ Picostat, User Manual

Page: 26 / 122

22 eDAQ Potentiostats
Range
When using Chart software on a Windows computer the Range control
limits the range over which the applied potential can be set. Smaller
ranges offer finer control with the slider bar of the applied potential,
Figure 2–7 . In Galvanostat mode this control changes so as to limit the
range over which the applied current can be set, Figure 5–17,
page 78 .
On a Macintosh computer use the values in Range control are affected
by the selection in the Stimulator Constant Output dialog box,
Figure
5–8, page 68 . and Table 5–1, page 81 .
Remember Potential
Check the box to remember the value of the
applied potential when the Potentiostat control window, Figure 2–7,
page 14 , is closed. (The potential value is transferred to the Stimulator
baseline control, Figure 5–5, page 67 ).
Maintenance
The Potentiostat will not require maintenance during daily operation.
However, you should periodically check the instrument for optimum
results by switching to potentiostat mode (with iR Compensation off)
and applying a known potential, E, to the Dummy Cell and checking
that the resulting current signal value, I, is in accordance with Ohm’s
law:
I = E/R
where R is the resistance, and is 1 MΩ for the dummy cell. Thus a
signal of 1 µA should be obtained when a potential of 1 V is applied,
1 µA with 2 V, etcetera. Try several different potentials and make sure
an appropriate current signal is observed in each case.
If this test produces the expected results then your Potentiostat is likely to
be functioning correctly. Next use the Potentiostat in Real Cell mode to
check the electrode cables by attaching them to a resistor (usually a
resistor of 10
3
–10
8
Ω is ideal) with the working electrode lead on one
side of the resistor and the auxiliary and reference leads connected to