Metrohm 840 PC Control 5.0 / Touch Control - Manual (Page 209)

4 Parameters
PC Control / Touch Control
197
4.1.1 Dynamic equivalence point titrations (DET) and monotonic
equivalence point titrations (MET)
For equivalence point titrations (DET, MET) the parameters are identical
except for a few exceptions. Both modes are described together here.
Under Start conditions the parameters for the initial addition of titrant
and for the initial measured value (measured value before start condi-
tions are processed) can be edited:
• Start volume (d
) : Volume which is added before the start of the ti-
tration. Under Dosing rate (d) you can enter the rate at which the
start volume is added.
• Pause (d): Waiting period which is to elapse before the start of the
titration after the start conditions have been fulfilled.
• Start measured value (d): Measured value at which the initial dos-
ing is stopped. Under Dosing rate (d) you can enter the rate to be
used until the start measured value or the start slope have been
reached.
• Start slope (d): Slope (measured value per unit volume) at which
the initial dosing is stopped. Under Dosing rate (d) you can enter
the rate to be used until the start measured value or the start slope
has been reached.
The start conditions are processed in succession: 1. Start volume,
2. Start measured value, 3. Start slope, 4. Pause.
Parameters for the Initial measured value:
• Signal drift (d): Drift, i.e. the alteration in the measured value per
minute, which has to be reached before the measured value will be
accepted.
• Waiting time min. (d): The measured value is not accepted until
the minimum waiting time has elapsed, even if the measured value
drift has already been reached. The minimum waiting time is only
important for drift-controlled measurements.
• Waiting time max. (d): If the signal drift is switched off or has not
yet been reached then the measured value will be accepted after
the maximum waiting time has elapsed.
Under Titration parameters you can edit the parameters for the titra-
tion procedure:
• Titration rate (d): Three predefined sets of parameters can be
selected for the titration rate (see Table on p. 199). If individual titra-
tion parameters need to be adapted you should select the setting
User and edit the individual titration parameters under User-
defined Parameters.
• Temperature (d): Manually entered titration temperature. If a tem-
perature sensor is connected and the temperature measurement is
set to automatic or continuous under Sensor (see Section 4.1.5)
then the temperature will be measured continuously. The value is
used for temperature compensation in pH measurements.