8
3.2.4 Deactivation/activation of the audible temperature 1 alarm
The audible alarm can be switched
or
. The factory setting is
, as otherwise an alarm could be trigge-
red immediately when the system is first put into service when the sensor is located outside the aquarium, where the
temperature may be either too high or too low .
3.3 pH programming
3.3.1 pH set point programming
The pH set point can be adjusted within the limits of 4 .0 – 9 .9 . If the measured pH value is outside the display range,
values lower than 4 .0 are displayed as
, values higher than 9 .9 are displayed as
. Outside of these limits,
the pH channel is switched off . The pH-controlled CO
2
fertilisation is carried out through permanent measuring by a
connected Dupla pH electrode and switching of a connected Dupla CO
2
magnetic valve with a switch hysteresis (the
difference between the switching point and the triggering point) of 0 .1 pH and a control accuracy is +/- 0 .1 . The
switch hystereris is pH 0 .1, and the control accuracy is +/- 0 .1 (reference value) . In order to ensure the accuracy of
measurement and therefore the control circuit, the Dupla Twin-Control pro provides an optional six-week calibration
memory function
Please note:
If no pH electrode is connected to the Dupla Twin-Control pro, so that the BNC socket is open,
fictitious pH values will be displayed.
3.3.2 CO
2
-night off function
This enables interruption of the CO
2
supply, controlled by a magnetic valve, into your aquarium during the night if
desired . The beginning and end times of the interruption during the night can be choosen after programming the pH
Set point .
3.3.3 pH alarm programming
A visual alarm indicated by flashing if the temperature exceeds or drops below the programmed desired pH values .
The factory presetting is , which means no alarm . The alarm window can be set between a pH 0 .1 and 4 .0 deviati-
on from the set point .
3.3.4 Deactivation/activation of the audible pH alarm
The audible alarm can be switched
or
. The factory setting is
, as otherwise an alarm could be trigge-
red immediately when the system is first put into service when the electrode is still located outside the aquarium or
not yet calibrated .
3.3.5 Calibrate pH electrode
The factory setting of the calibration points are pH 7, pH 4 and pH 9, the calibration sequence is first pH 7, then pH 4
or pH 9 . The calibration process can be cancelled by pressing the
▲
and
▼
buttons simultaneously .
3.3.6 Reminder of calibration function
With this feature enabled, every six-weeks
CAL
and flash on the display as a reminder to check the pH electrode
calibration . For a period of 10 seconds you will hear a beep every 2 seconds . This will be repeated every hour .
If you prefer not to carry out a calibration, the memory display clears after activating any button and reappears in
another 6 weeks .
In order to calibrate the pH electrode, enter programming mode by pressing the
button and follow item 5 .3 .4 of
the instructions .
To disable of the calibration memory function, continue to scroll through the menu items and set the function to
.
