Metrohm 840 PC Control 5.0 / Touch Control - Manual (Page 230)

4.1 Titrations
218
PC Control / Touch Control
Dosing within the control range:
Within the control range the dosing rate is mainly characterized by the
minimum rate .
The parameters for the titration sequence are edited under Titration
parameters :
• Titration direction: The titration direction is normally deter-
mined automatically from the initial measured value and the set
control point. It is recommended that, whenever possible, a positive
or negative alteration of the measured value is entered.
• Temperature: Manually entered titration temperature. If a tempera-
ture sensor is connected and 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.
• Time interval MP: Time interval for entering a measuring point in
the list of measuring points.
• Start time: The measured values are not entered in the list of
measuring points until this time has elapsed since the start of the ti-
tration.
• Start measured value: The measured values are not entered in
the list of measuring points until this value has been reached.
• Start rate: The measured values are not entered in the list of
measuring points until the dosing rate has fallen below this value.
This parameter is checked 10 s after the start at the earliest.
If several start parameters have been defined, all of them must be ful-
filled for a measured value to be entered in the list of measuring points.
The conditions for terminating the titration are defined under Stop con-
ditions :
• Stop volume: Stops when the preset volume has been added since
the start of the titration.
• Stop time: Stops when the preset time has elapsed after the start
conditions have been fulfilled.
• Since: Specifies the beginning of the stop time.
Start : The stop time starts after the start conditions have been ful-
filled.
Control reached
: The stop time starts as soon as the control point
has been reached for the first time.
Last dosing
: The stop time starts after the last increment has been
dosed, i.e. the stop time is reset to zero again after each dosing
step.
• Stop rate: Stops when the current titration rate is lower than the
rate defined here.
If several stop conditions have been set then the first criterion to be ful-
filled will stop the titration.