eDAQ e-corder, Manual

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Chapter 3 — The Dual Picostat 35
Signal Display
The current signal is previewed scrolling across the display area. Note
that the signal is not being recorded to hard disk at this stage, and that
when the window is closed the signal trace is lost.
You can stop/start the signal scrolling by clicking the Pause/Resume
button .
You can shift or stretch the vertical Amplitude axis to make the best use
of the available display area. All changes to axis scaling are reflected
in the Chart and Scope main window, and vice versa.
Setting the Range
The Range pop-up menu lets you select the input current range or
sensitivity. The Dual Picostat has ranges of 2 pA to 10 μA (if you
require a system to monitor larger currents, use the eDAQ Potentiostat
which has ranges up to 100 mA). Set the range so that it is larger than
the biggest current that you expect to encounter during your
experiment. If, during the experiment the current signal exceeds the
range, then the data will be truncated.
Filtering
The Off setting gives the full bandwidth of the Dual Picostat which can
be up to 16 kHz (but which may also be limited by the characteristics
of your electrodes and sample solution). The Dual Picostat has an
internal 10 Hz low-pass filter that can be turned on for removal of high
frequency signals (‘noise’). Other low pass filter settings are provided
by the
e-corder unit.
The 10 Hz filter setting is highly effective for the removal of mains hum
(50 or 60 Hz interference) and, as a general rule, should be employed
whenever possible. However, it should not be used for either pulse
amperometric or voltammetric experiments where the pulses are shorter
than 100 ms, or for voltammetric experiments where fast scan rates
(greater than 100 mV/s) are used, or for other signals which are likely
to exhibit fast rise or fall times — otherwise excessive smoothing of the
signal may occur.