Operating Controls; Setting The Working Temperature; Setting The Timer; Temperature Alignment - Velp Scientifica VTF Bedienungsanleitung

3. Operating controls

Install the thermoregulator on the support rod and place the probe in the liquid to be
processed. To power the VTF plug the spiral cable into the dedicated socket on the heating
magnetic stirrer and turn the stirrer on. The display shows the software version after which it
flashes for approximately five seconds showing last set point (Fig. 4).
The current Pt100 probe temperature reading is then displayed on the main window. Thermoregulation starts automatically
based on temperature Set Point selected.
NOTE: the magnetic stirrer always exercises primary control of the heating plate temperature. To control the heating plate
temperature using the VTF thermoregulator, set the magnetic stirrer temperature to maximum. The magnetic stirrer
temperature control can also be used as a safety thermostat since the heating plate will not exceed the temperature set on
the stirrer. In this case, longer heating time will be necessary in order for the sample to reach the VTF set point temperature.

3.1 Setting the working temperature

From the main window, press the central
Set Point Temperature
Set Point Temperature
With the display is flashing use the
The temperature setting is saved when no keys are touched for approx. 5 seconds (Fig. 4).
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 the key 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 the
Working time
With the display flashing use the
To switch from hours to minutes press the
With the display flashing use the
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
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" (Fig. 9).
To return to the main window in order to start new work-cycle, press
0:00 and the maximum temperature reached can be viewed by pressing
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 the
The time left is automatically reset to zero every time the instrument is turned off.

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
Turn the instrument on by keeping the
keys to modify the "Temperature alignment" parameters (Fig. 10).
Use the and
If no key is pressed for 5 seconds the display shows the software version and the default set point value.
If no key is pressed for a further 5 seconds the display shows the probe temperature reading and saves the value.
button. The set-up window is displayed (Fig. 4).
From -10 to +300 °C
From -10 to +400 °C
and keys to select the temperature required.
key twice to display the working time.
From 00:00 to 24:59 (h:min.)
and keys to select the working time required.
key once or simply wait 4 seconds (Fig. 7).
and keys to select the working time required.
From - 9.9 to + 9.9 °C
From - 17 to + 17 °F
and keys pressed.
Default value: 10 °C, for VTF
Default value: 10 °C, for VTF EVO
Default value: 0:00 (Fig. 6)
.Working time will return to the default value of
. Working time can be changed when VTF is in
key pressed.
Default value 0.0 °C
0.0 °F
7
Fig. 4
°C
Fig. 6
Fig. 7
°C
Fig. 8
Fig. 9
°C
Fig. 10