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Metrohm 757 VA Computrace User Manual

Page 46

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3 General settings for exploratory and determination mode

757 VA Computrace – Software

36

Sweep parameters:

Hydrodynamic (measurement) [ on, off ; off ]

Enable/disable stirring of the RDE/SSE during the sweep.

Start potential (V)

[ -5...+5 V ; -0.9 V ]

Start voltage for the voltage sweep.

End potential (V)

[ -5...+5 V ; -0.1 V ]

Final voltage for the voltage sweep.

Voltage step (V)

[ > 0 V ; 0.006 V ]

Voltage step for direct voltage ramp.

Voltage step time (s)

[ > 0 s ; 0.4 s ]

Time interval after which the voltage in the sweep is in-
creased or decreased by the amount

Voltage step

.

Sweep rate (V/s)

[ read only ]

Display of the ramp slope calculated as

Voltage step / Voltage

step time

.

Notes:
• The DC measurement mode can be used with all types of

electrodes except for DME and SMDE in the determination
mode.

• The following conditions apply to the definition of the

Voltage

step time

:

Voltage step time > 270 µs

(HMDE/RDE)

Voltage step time > 20 ms

(DME)

Voltage step time > Drop size × 40 ms + 10 ms

(SMDE)

• The measurement time

t (i)

is defined as follows:

t (i) = 20/16.67 ms

(50/60 Hz)