SI Analytics TitroLine 7500 KF Mode D'emploi page 123

Minimum titration time
The minimum titration time can be set between 0 – 9999 seconds. The default setting is 10 seconds. The
minimum titration time prevents premature termination of the titration if there is a delay in the extraction of water
from the sample. The minimum titration time is used in combination with the extraction time. It expires while the
extraction time is still active.
Maximum titration volume
Setting of the maximum titration volume should always make sense. It also serves as a safety criteria to
prevent excessive titration, i.e. a possible overflow of the titration vessel. The maximum titration volume can be
set between 1.000 und 999.999 ml:
Fig. 97
The default setting is 50 ml. The volume for conditioning is included in the count!
Drift
The drift is calculated in µg/min from the titration mean consumption/time x concentration of the titration solution.
A stable drift at the beginning and end of the titration is important if you want to obtain reproducible results. This
applies in particular to samples with low water content in the bottom percentage range (<0,1%). The drift value
should also not be set too low because the titration time will increase considerably. An airtight and dry titration
vessel has a drift of < 50 µg/min. This corresponds to consumption of 10 µl (0,01 ml) of titrant at a concentration
of 5 mg/ml. For many applications, a drift value of 100 – 150 µg/min is entirely sufficient. The default drift value
setting is 100 or 150 µg/min for sample titration. 50 µg/min is the default setting for titer methods.
Endpoint µA
The range of the µA input can be selected between 0.0 and 100.0. For KF titration, values between 10 – 30 µA
are practical. The standard value is 20 µA.
Delta Endpoint µA
The Delta value in µA is one of the most important parameters for KF and dead-stop titration. The lower the Delta
value is, the longer the titration (dosing) is at a continuous speed. When using single-component reagents and
pure methanol as a solvent, the Delta value should be set at < 5 µA. Values of 2 or 3 µA are practical. This is
because the KF reaction in methanol runs relatively slowly. When using double-component reagents or also
when using combination solvents, the Delta value must be set at > 10 to prevent rapid overtitration. Values of 14
or 15 µA are practical.
Endpoint delay
The endpoint delay is set in seconds. It can be set from 0 – 100000 seconds. The standard value is 10 seconds.
Brief endpoint delays (5 seconds) are practical when
•
using very small increments (e.g., 0,001 ml)
•
using a titer of 1 mg/ml
•
creating a secondary reaction with a higher drift value
Chapter 4 Method Parameters
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