Metrohm 746 VA Trace Analyzer - Manual (Page 372)

5.7.3 Alphabetical instruction list
746 VA Trace Analyzer / 747 VA Stand
5-221
CYCMODE Page: O, S Stand: M, A Abbreviation: CY
Instructions t/s Main parameters Auxiliary parameters
––––––––––––– ––––– ––––––––––––––––––––––––– –––––––––––––––––––––––––
## .. CYCMODE ..... I.range ........uA Prep.cycles ........
Meas.cycles ........
Function Measurement mode for cyclic voltammetry.
Application Cyclic voltammetry is mainly used to investigate reversible electrode
processes and for kinetic studies.
Parameter Range; Default value / Meaning
I.range 800, 450, 140, 45, 14, 4.5, 1.4, 0.45, 0.14, 0.045 uA; 14 uA
Maximum current measurement range ( -I.range...+I.range )
This parameter is used to set the sensitivity of the current measurement
for the cyclic sweep.
I.range must always be larger than the maximum
measured, absolute current values I
cath
and I
an
, otherwise current values
> I.range are cut off. However, the value selected for the current
measurement range should not be too large, otherwise the sensitivity of
the current measurement is lowered unnecessarily.
Prep.cycles 0...99; 0
Number of preparation cycles
This parameter specifies how often the subsequent CSWEEP block
should be executed before the actual measurement without a current
measurement being performed.
Meas.cycles 0...9; 1
Number of measurement cycles
This parameter specifies how often the subsequent CSWEEP block
should be executed on completion of the preparation cycles for the
actual current measurement
Description With the CYCMODE measurement mode, direct voltage ramps can be
applied to the working electrode with a high voltage sweep rate. If the
initial and final potential are identical, this is known as cyclic voltamme-
try. The current I is measured as a function of the voltage U. The nature
of the measurement is shown below using the HMDE as an example.
Comments • The CYCMODE measurement mode can be used only with the
electrode types HMDE and RDE and must be employed together with
the block for the cyclic voltage sweep (CSWEEP...CSWEEP) and the
ramps RAMP it contains.
• The electrode type HMDE or RDE must be entered before the CYCMODE
measurement mode.