eDAQ Picostat, User Manual

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56 eDAQ Potentiostats
When you use the Chart and Scope software, there is a Mains Filter
checkbox. If this is ticked, then the
e-corder will apply a mains filtering
algorithm to the incoming signal which removes repetitive signals
occurring at 50 or 60 Hz which are typical of mains interference. Note
that the mains filter is NOT a simple notch filter, and it can remove 50
or 60 Hz interference even if it is not a pure sinusoidal waveform.
However, the mains filter does take a few seconds to ‘learn’ the pattern
of the interference so that you will need to record for longer than this
for it to take full effect. The mains filter can even be employed for
experiments in which there are sudden potential jumps.
Inverting the Signal
The Invert checkbox allows you to invert the incoming current signal. It
provides a simple way to redefine the directions (up or down) of an
anodic (or cathodic) current signal. This control
does not affect the
direction of current flow at the electrodes.
Cell Control
The QuadStat can be in one of three operating modes, controlled by
the Cell radio buttons:
• Standby : If Standby mode is selected the auxiliary and reference
electrodes are isolated by an internal relay which effectively means
that all the electrodes are at a ‘floating’ potential and that no current
will be passed through your experimental solution. The electrodes
will not be connected until the QuadStat control dialog is closed and
the Chart, Scope or EChem Start button is clicked to begin a scan.
The Applied Potential control is disabled in this mode.
• Dummy : When Dummy mode is selected the QuadStat channel is
connected to the internal 1 MΩ dummy cell. You can then use the
Applied Potential slider control to vary the voltage applied to the
dummy cell. The QuadStat will remain connected to the dummy cell
even when the QuadStat Control window is closed and Chart,
Scope or EChem is recording. This is useful for testing the QuadStat.
• Real : In Real mode the electrodes will be active and the Applied
Potential slider control can be used to adjust the potential. When
you close the control dialog (using EChem software) the QuadStat
will revert to Standby mode until the Start button is clicked to begin
a scan. If you are using Chart or Scope software, the QuadStat will