Technical Data - Sera PRECISION seramic Mode D'emploi

tion, but slowly drifts into one direction, the electrode is
dirty and needs cleaning. Immerse the tip of the pH elec-
trode in the sera cleaning solution for 10 – 15 minutes.
You must never clean the pH electrode with common
cleaning solutions, cloth, brush or the like! After cleaning,
soak the pH electrode in sera care solution for 12 hours,
then rinse with distilled water and recalibrate.
c) The pH electrode must stay moist always. It gets dry with-
in a short time when it comes in contact with air and may
lead to incorrect measuring results! In such cases, soak
the pH electrode for 12 hours then recalibrate.
d) Water change
Before the water change, remove the pH electrode and
put it into the protection cap filled with aquarium water.
Otherwise, the electrode will dry out when the water level
is lowered, which requires recalibration.
If the electrode is dried out, it creates havoc on the con-
troller unit and display false pH value. Should the elec-
trode accidentally report an alkaline value, the solenoid
valve will open and causes uncontrollable CO
the aquarium. The pH electrode does not react anymore,
thus it leads to rapid decrease of the pH value in the
aquarium.
There is, however, a possibility to leave the electrode in
the aquarium during water change. Drill a hole of 12 mm
(0.45 in.) diameter into a postcard-sized Styrofoam plate
with a thickness of about 25 mm (1 in.). Insert the pH elec-
trode into this hole and let it float during the water
change.
Important! When applying this method, do not lower the
water to the extent that the tip of the pH electrode is in
contact with the stones or gravel at the bottom.
e) Ageing
Although the pH electrode can be optimally cared for
with sera cleaning solution and sera care solution KCl,
every pH electrode is technically subject to ageing.
Symptoms of ageing are, delayed reaction time, inaccu-
rate and drifting display values, etc. In this case, replace
the pH electrode.
7. Description of regulation behavior
Control is achieved by a 2-point regulation. If the pH value
exceeds the adjusted pH value, the solenoid valve is opened
for CO addition. If the pH value drops by 0.05 pH units below
2
the adjusted pH value, the solenoid valve closes again (regu-
lation hysteresis of 0.05 pH units).
The regulation range of the system is within a pH range be-
tween 5.0 and 9.0, the desired pH value can only be adjusted
in this range.
The operation mode of the solenoid valve is displayed by a
green light-emitting diode. If the valve is open, the green
light-emitting diode is on. When the valve is shut off the light-
emitting diode is off.
10

8. Technical data

pH controller unit
with user guided calibration
4-digit display (LCD), 12.5 mm high
Case protected against water splashing according to protection
mode IP 65.
The socket for connection of the pH electrode (electrode plug) is not
moisture protected. If this socket is exposed to moisture, it will cause
incorrect pH measuring value. This will lead to uncontrolled CO
lease into the aquarium.
Voltage requirement
Power consumption
Accuracy
Measuring range
Control range
Input resistance of electrode
Pneumatic bulkhead fittings
for hose: 4/6 mm
Electrical data of dosage valve
Nominal width 1.2 mm
flow into
2
Trouble shooting and error checklist
re-
2
230 V / 50 Hz
(optional) 115 V / 50 Hz
c. 2.5 watts
± 0.05 pH units
pH 2 .. 12
pH 5 .. 9
≥10
14
Ohms
24 VDC / 2 watts