Metrohm 746 VA Trace Analyzer - Manual (Page 148)

4.6 Basic method for DPASV
746 VA Trace Analyzer / 747 VA Stand
4-63
2 Switch to dialog page "SEGMENT"
• Press the yellow key. The dialog page "SEGMENT"
appears with the program for measured value acquisition:
Method: ASV SEGMENT
ASV
Instructions t/s Main parameters Auxiliary parameters
ДДДДДДДДДДДДД ДДДДДДДДДДДДД ДДДДД ДДДДД ДДДДДДДДДДДДДДДДДДДДДДДДД ДДДДДДДДДДДДДДДДДДДДДДДДД
ДДДДДДДДДДДДДДДДДДДДДДДДД ДДДДДДДДДДДДДДДДДДДДДДДДД
1 STIR 5.0 Rot.speed 2000 /min
2 HMDE Drop size 4 Meas.cell normal
3 DPMODE U.ampl 50 mV t.meas 20.0 ms
t.step 0.10 s t.pulse 40.0 ms
4 MEAS 90.0 U.meas -1150 mV
5 ØSTIR 5.0
6 SWEEP 21.9 U.start -1150 mV U.step 6 mV
U.end 150 mV Sweep rate 60 mV/s
7 ØMEAS U.standby mV
8 END
Modify
column
Modify
line
Delete
instr.
Insert
instr.
Select
segment
Delete
segment
Plot
param.
Segment
name
• The sequence of the segment ASV is explained in brief in what follows:
Line 1 Stirring of the analysis solution for 5 s
Line 2 Switching on the HMDE (hanging mercury drop electrode)
Line 3 Selection of the measurement mode DP (differential pulse)
with voltage amplitude 50 mV, voltage step 0.1 s,
measurement time 20 ms and pulse time 40 ms
Line 4 Application of a measurement voltage of –1150 mV for
90 s for the enrichment at the hanging mercury drop
Line 5 Switching off the stirrer and stabilization of the analysis
solution for 5 s
Line 6 Voltage sweep from –1150 mV ... 150 mV with a voltage
step of 6 mV
Line 7 Switch off voltage and current measurement
Line 8 End of segment (return to main program)
3 Switch to dialog page "SUBSTANCES"
• Press the yellow key. The dialog page "SUBSTAN-
CES" appears with the parameters for evaluation of substances. Only
one substance Subst1 with standard parameters without an entry for the
characteristic voltage U.verify is defined.
• Press the softkey < >> > . The subpage of "SUBSTANCES" appears with
the parameters for calibration. There is no calibration for the substance
Subst1
(
Technique = none
).
4 Switch to dialog page "CALCULATION"
• Press the yellow key. The dialog page "CALCULA-
TION" appears for calculation of the final results. No formulae are en-
tered.