Metrohm 757 VA Computrace - Manual (Page 86)

5 Determination mode
757 VA Computrace – Software
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Cell volume (mL) [ > 0 mL ; 10 mL ]
Total volume of solution (sample + auxiliary solu-
tion, e.g. buffer) in the measuring vessel at the
start of the determination. The sample concentra-
tions Mass conc. calculated refer to this cell
volume.
Measure blank [ on, off ; off ]
Measure a blank solution before sample deter-
mination. The blank curve is then automatically
subtracted from all subsequent measured
curves. This background compensation is mainly
used to reduce interference due to the support-
ing electrolyte. Such interference includes both
the presence of the analyte (blank value) and that
of foreign substances electroactive in the same
range. The blank curve is only recorded once (no
replications).
No. of blanks [ 1...5 ; 1 ]
Number of measurements to determine the blank
curve. If the blank solution is measured several
times, a mean blank curve is determined from
the different measurements.
Blank purge time [ 0...80600 s ; 300 s ]
Time of inert gas purging before measurement of
the blank solution.
Addition purge time [ 0...80600 s ; 10 s ]
Time of inert gas purging for all measurements
after determination of the sample (standard addi-
tion) or of the first calibration solution if
Batch is
selected for Technique (for the first measurement,
the Initial purge time is used).
Cell purge time [ 0...80600 s ; 10 s ]
Time of inert gas purging after solution exchange
if
Batch with solution exchange is selected for
Technique (for the first measurement, the Initial
purge time is used).
No. of additions [ 0...28 ; 2 ]
Number of additions of standard addition solu-
tions or calibration solutions if
Batch is selected
for Technique .
No. of cells [ 0...28 ; 2 ]
Number of solutions to be measured if Batch with
solution exchange is selected for Technique .
Calibration curve [ path + file name ; ]
Selection of the determination file with the re-
corded calibration curves to be used if
Sample
with calibration curve is selected for Calibration .