Chemglass CG-1995-V-20 - Manual (Page 3)

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If no key is pressed for approx. 5 seconds when the set-up window is flashing, the value shown on the display is
automatically saved. After 5 seconds the VTF will evaluate the temperature reading of the probe immersed in the liquid and
will proceed to thermoregulate the liquid to the temperature selected.
NOTE: to display the maximum temperature reached since the instrument was turned on, with the main window displayed
keep
“↑” pressed. The maximum temperature reached is deleted from the memory every time the instrument is turned off.
3.2 Setting the timer
From the main window press
“SET” twice to display the working time.
Working time From 00:00 to 24:59 (h:min.) Default value: 0:00 (Fig. 6) Fig. 6
With the display flashing use “↑” and “↓” to select the working time required.
To switch from hours to minutes press “SET” once or simply wait 4 seconds (Fig. 7).
Fig. 7
With the display flashing use “↑” and “↓” to select the working time required.
The value is saved when no keys are touched for approx. 5 seconds. If no key is pressed for
5 seconds the display returns the main window and the previously displayed value is saved.
Count-down starts the moment the working time has been saved. The alternate flashing of
Fig. 8
the two arrows to the left of the display indicates that the VTF is running in timer-mode (Fig. 8).
At the end of the working time the instrument automatically turns off the thermoregulation, and the display shows
“End”.
To return to the main window in order to start new work-cycle, press “SET”. Working time will return to the default value of
0:00 and the maximum temperature reached can be viewed by pressing “↑”. Working time can be changed when VTF is in
use even if the instrument is running in timer-mode. If working time is set to 0:00 the instrument will run in continuous mode.
NOTE: to display the time left, with the main window displayed keep
“↓” pressed.
3.3 Temperature alignment
The micro-chip carries out automatic probe calibration therefore a probe calibration procedure is unnecessary.
Nevertheless, an offset value of from - 9.9 to + 9.9 °C can be set.
Temperature alignment From - 9.9 to + 9.9 °C Default value 0.0 °C
From - 17 to + 17 °F 0.0 °F
Turn the instrument on by keeping “SET” and “↓” pressed.
Use “↑” and “↓” to modify the “Temperature alignment” parameters (Fig. 9). Fig. 9
If no key is pressed for 5 seconds the display shows the software version and the last set point value.
If no key is pressed for a further 5 seconds the display shows the probe temperature reading and saves the value.
3.4 Unit of measure
Turn the instrument on by keeping
“SET” and “↓” pressed. Use “↑” and “↓” to modify the “Unit of measure”.
If no key is pressed for 5 seconds the display shows the software version and the last set point value. If no key is pressed
for a further 5 seconds the display shows the probe temperature reading in the new unit of measure and saves the value.
3.5 Safety devices and error signals
The instrument has an in-built safety and control circuit which is constantly active and shuts-down the VTF in case of:
• unconnected probe
• faulty probe (cut-off or short circuited) • temperature out of range (- 10…+300 °C)
Thermoregulation stops and the error message “Err” appears on the display.
To reset the thermoregulator turn it off and on again after having found and removed the cause of the alarm.
4. Start-up
• Install VTF on the support rod and immerse the probe by 15mm, making sure it does not get in contact with the container;
• Make sure the magnetic stirrer is turned on;
• Power VTF by plugging the spiral cable into the dedicated socket on the heating magnetic stirrer;
• Set the magnetic stirrrer temperature to maximum;
• Select the temperature and the working time required;
• To optimize thermoregulation and improve temperature homogeneity, stir the sample gently but continuously.
WARNING
• If working with set points near the evaporation temperature, the probe has to be immersed by 10mm throughout the cycle;
• The sample being processed is subject to evaporation and for this reason it may not reach the temperature selected.
5. End-of-work operations
To interrupt thermoregulation and leave the VTF thermoregulator powered, turn off heating plate using the knob on the
magnetic stirrer. In this way heating stops but the VTF continues to display the temperature. If the timer has been set, the
VTF will autom
atically stop at the end of the set time and the display will show “End”. To reactivate thermoregulation press
“SET”. At the end of the process, if the VTF has to be left connected to the magnetic stirrer, turn the stirrer off.
6. Maintenance
No routine or extraordinary maintenance is necessary apart from periodically cleaning the unit as described in this manual.
In compliance with the product guarantee law, repairs to our units must be carried out in our factory, unless previously
agreed otherwise with local distributors. The instrument must be transported in its original packaging and any indications
present on the original packaging must be followed (e.g. palletized).
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