8
3.4 Unit of measure
Turn the instrument on by keeping the
and
keys pressed.
Use the
and
keys to modify the
“Unit of measure” (
Fig. 11)
.
Fig. 11
If no key is pressed for 5 seconds the display shows the software version and default 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 alarm signals
The instrument has an in-built safety and control circuit which is constantly active and shuts-down the VTF when an alarm
message appears on the display:
-
AL .1 = Unconnected probe or faulty probe (cut-off or short circuited) or temperature out of range.
-
AL .2 = Slow temperature increase read by the probe. This function is active in case of:
•
Probe temperature < 50°C
•
T set point
– T probe > 5°C
-
AL .3 = Fast temperature decrease read by the probe.
To reset the thermoregulator turn it off and on again after having found and removed the cause of the alarm.
In order to bypass the AL .2 and AL .3, turn the instrument on by keeping the
and
keys pressed and select AL.oF
using
and
keys. Press
to confirm
.
4. Start-up
• Install the VTF/VTF EVO on the support rod so that the probe is immersed in the liquid by at least 15mm making sure that
it does not make contact with the bottom of the container;
• Make sure the magnetic stirrer is turned on;
• Power the VTF/VTF EVO 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
• When working with set points near the temperature of evaporation, check that the probe remains immersed in the sample
by at least 10mm throughout the work-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 automatically stop at the end of the set time and the di
splay will show “End”.
To reactivate thermoregulation press
.
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).
It is the responsibility of the user, to properly decontaminate the unit in case of hazardous substances remaining on the
surface or interior of the device. If in doubt about the compatibility of a cleaning or decontamination product, contact the
manufacturer or distributor.
6.1 Cleaning
Disconnect the unit from the power supply and use a cloth dampened with a mild, non-flammable detergent.
