Heidolph Hei-VAP Precision - Manual (Page 40)

Operation Operation
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Start pressure ramp
The pressure ramp is started with softkey “start all“ (1) or “start vacuum“ (1).
The pressure/time segments are processed.
Note: The maximum attainable increase of the pressure/time curve is limited by the
pump capacity and the leak rate of the system.
The process is terminated when reaching the last entry. The vacuum control is switched
off, the system is ventilated. The lift is raised with a motorized lift. The heating bath is
switched off depending on the setting in the setup.
Calling up the pressure ramp
Pressure ramps can be called up via the Favorites menu.
The programmed pressure ramps can be edited when the process is de-activated by
changing the respective parameters (see chapter “Operation” – “Gradient function”).
Softkey Graph
The pressure curve is displayed in the graphic view of the actual value display. The time
is illustrated in [min] on the x axis and the associated pressure in [mbar] on the y-axis.
1. Select the pressure/time step to be changed by turning the rotary pushbutton
controller Hei-GUIDE (6).
2. Confirm the selection by pressing the Hei-GUIDE (6).
3. The value can be changed by turning the Hei-GUIDE (6) to the left or right.
4. The current setting is accepted by pressing the Hei-GUIDE (6).
The data record can be saved by using softkey “Store Favorite“ (1).
Softkey “Esc“ (1) discards the changes and returns to the actual value display.
A graphic overview of the programmed ramp is displayed by using softkey “Graph“ (1).
The gradient diagram presents the time on the x-axis in [min] and the related pressure
on the y-axis in [mbar].
The scaling of the x and y axes is illustrated so that all of the entered times or pressures
are illustrated.
The entry “enter basic settings” returns to the time-unrelated basic values of the heating
bath, rotation, hysteresis, and the max. power pump.
Softkeys
Softkey “Start all” and “Stop all”
A distillation can be started and stopped automatically by using softkey “Start all” (1)
and “Stop all” (1).
The unit is operational.
The immersion depth of the evaporator flask is set (see chapter “Set-up and start-up“
– “Glassware sets”).
The desired settings are completed.
Caution - Glass breakage! The immersion depth of the evaporator flasks
must be set correctly to prevent lowering of flask into bottom of heat
bath on motor lift models.
Switching over between “graph” and “values” is not possible when the
vacuum control unit is switched off.
Only the section for which pressure values are available is shown on the pressure axis.
The displayed time range on the x-axis is set in the setup. If the set time range is
exceeded, the time window will be continuously shifted.
”Start all”
The lift moves down (only for the motor lift unit), rotation, vacuum control and timing are
started.
All parameters of the distillation can be changed during the course of
the “start all” function.
”Stop all”
The lift moves upward (only for the motor lift unit), rotation, vacuum control and timing
are stopped.