Metrohm 797 VA Computrace - Manual (Page 104)

5 Determination mode
797 VA Computrace – Software
92
Cell volume (mL) [ > 0 mL ; 10 mL ]
Total volume of solution (sample + auxiliary solu-
tion, e.g. buffer (added manually or pre-dosed
with a Dosing Device)) in the measuring vessel at
the start of the determination. The sample con-
centrations
Conc. calculated refer to this cell vo-
lume.
Note: The sample and solution parameters ( Sample identifier ,
Sample amount , Sample unit , Cell volume ) are different with the
CVS or CPVS mode.
Measure blank [ on, off ; off ]
Measure a blank solution before sample determi-
nation. The blank curve is then automatically sub-
tracted from all subsequent measured curves. This
background compensation
is mainly used to re-
duce interference due to the supporting electro-
lyte. Such interference includes both the presence
of the analyte (blank value) and that of foreign
substances electroactive in the same range.
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 af-
ter 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).
Note: The blank measurements parameters ( Measure blank , No. of
blanks , Blank purge time , Addition purge time ) are different with
the CVS or CPVS mode.
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 .
No. of additions [ 0...28 ; 2 ]
Number of additions of standard addition solu-
tions
resp. calibration solutions if Batch is selected
for Technique .