Metrohm 746 VA Trace Analyzer - Manual (Page 374)

5.7.3 Alphabetical instruction list
746 VA Trace Analyzer / 747 VA Stand
5-223
DCTMODE Page: O, S Stand: M, A Abbreviation: D
Instructions t/s Main parameters Auxiliary parameters
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## .. DCTMODE ..... t.step ........s t.meas ........ms
Function Measurement mode for direct current voltammetry
(DCT = Direct Current Tast).
Application Direct current voltammetry is the classic, simplest VA method with limited
sensitivity. It is mainly used for the investigation of reversible redox
systems.
Parameter Range; Default value / Meaning
t.step 0.05...9.9 s; 0.3 s
Time interval for voltage step
Time interval after which the voltage in the sweep is increased or
decreased by the amount
U.step .
The following condition applies to the definition of t.step :
t.step > t.meas + t.drop + 30 ms
t.meas 1.0...64.0 ms; 40/50 ms for 50/60 Hz
Measurement time
Time during which the current measurement takes place. Measurement
is performed at the end of the time interval
t.step .
Description With the DCTMODE measurement mode, the direct voltage applied to the
working electrode is continuously changed and the resultant current I
which flows measured as a function of the voltage U. The nature of the
measurement is shown below using the SMDE as an example.
Adjustable parameters:
DCTMODE
t.step
t.meas
SWEEP
U.start
U.end
U.step
F (Hg)
t.drop
t
U
t
U.step
U.start t.step
t.meas t.meas
Area (Hg)