eDAQ Picostat, User Manual

Page: 66 / 122

62 eDAQ Potentiostats
Introduction
The Potentiostat, Picostat, and Quadstat apply a potential difference
across a pair of working and reference electrodes whilst monitoring the
current flow between the working and auxiliary electrodes.
This potential difference is determined by a ‘command voltage’ which is
sent from the
e-corder output to the ‘E In’ connector of the Potentiostat,
Picostat, Figure 3–3, on page 29, Potentiostat, Figure 2–4, on page 9
or QuadStat, Figure 4–2, on page 44 . The QuadStat can also generate
a constant command voltage internally. Chart and Scope software
control the
e-corder output via the ‘Stimulator’ controls in their Setup
menus. For a full description of these controls, and the waveforms that
can be produced, you should consult the
Chart Software Manual and
Scope Software Manual .
You can use your e-corder and Potentiostat, Picostat, or QuadStat with
Chart and Scope software to perform the following experiments:
• Linear Scan techniques, page 63 — use Scope software with the
Potentiostat to provide a potential ramp (up to 500 V/s) and to
subtract charging current contributions. The bandwidth of the
Picostat and QuadStat are sufficient for scan rates up to about
10 V/s
• Chronoamperometry page 65 & page 74 , Amperometry,
Constant Potential Electrolysis, page 82 , — monitor the current
signal at fixed potentials
• Chronocoulometry page 75 — monitor and integrate the current
signal at a fixed potentials
• Chronopotentiometry page 77 , Constant Current Electrolysis
page 83 — monitor the potential signal when the Potentiostat is
used as a galvanostat to maintain a constant current at the working
electrode. Note that the Picostat and QuadStat cannot be used as
galvanostats
• Monitoring of amperometric sensors page 84 , including dissolved
oxygen and nitric oxide electrodes.
• zero resistance ammeter, or high impedance voltmeter, with the
Potentiostat,
page 15 .
NOTE
The QuadStat also has
internal potential
adjustment of ±2 V.
When the e-corder
output is connected to
a QuadStat channel
‘E in’, this value is
summed with the value
set by the Chart or
Scope Stimulator
controls, to a maximum
of ±10 V.