Metrohm 757 VA Computrace - Manual (Page 44)

3 General settings for exploratory and determination mode
757 VA Computrace – Software
34
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.
Amplitude (V) [ > 0...+1 V ; 0.05 V ]
Voltage amplitude of the square wave voltage superim-
posed on the direct voltage.
Frequency (Hz) [ > 0...2000 Hz ; 50 Hz ]
Frequency of the superimposed square wave voltage, which
defines the voltage step time (
Voltage step time = 1 / Fre-
quency ).
Sweep rate (V/s) [ read only ]
Display of the ramp slope calculated as Voltage step × Fre-
quency .
Notes:
• The SqW measurement mode can only be used with HMDE
or RDE electrodes.
• The following condition applies to the definition of the
Voltage
step time :
Voltage step time = 1 / Frequency > 250 µs
• The measurement time
t (i) is defined as follows:
Voltage step time ≥ 80 ms → t (i) = 20/16.67 ms (50/60 Hz)
Voltage step time < 80 ms → t (i) = 0.5 × Voltage step time