Aquacontrol SL3 Deluxe 1,6 l/h, Manual

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Page 29
3.9 Calibration of pH – probe
As pH test probes are subject to a certain varia-
bility, they have to be calibrated to the measur-
ing and control unit in question. Before com-
mencing operation, remove the protective cap
from the probe. The probe must be free of im-
purities, oils and fats. The diaphragm (small
point at the tip of the probe) must be free of
deposits, dirt and efflorescence. For that reason,
the glass body should not be handled. (see:
cleaning and maintenance)
After probe and control unit have been con-
nected to the measuring pipe, the probe is
dipped into the pH7 buffer solution. Caution:
Please ensure that the plug and the cable are
kept absolutely dry. Note: Do not confuse the
connections. (left-hand socket)
The following menu items are selected using the
“OK” key:
To activate the calibration routine, press “OK”
key again.
After 15 seconds, the control unit displays the
value of the buffer solution used.
If the value does not match the pH 7 buffer
used, it can be corrected to pH 7 using the ar-
row keys.
Afterwards, take the probe out of the first buff-
er solution and if possible rinse it in water and
dry it off using a dry paper towel that does not
shed threads (i.e. no napping).
Caution: Do not rub the probe dry, as this leads
to an electrostatic charge and distorted measure-
ment.
Now dip the probe into the second pH 4 buffer
solution.
Press “OK” to trigger Part 2 of the calibration
routine.
After a further 15 seconds, the control unit dis-
plays the value of the second pH 4 buffer solu-
tion.
The value is confirmed by pressing the „OK“
key. If the figure does not match the pH 4 buff-
er used, it can be corrected to pH 4 using the
arrow keys.
If the calibration was successful, the measured
values such as zero point and slope of the elec-
trode are displayed. Press the „OK“ key again to
confirm the calibration
.
The control unit has now been successfully cali-
brated to the pH probe.
Calibration
pH
Controller (1)
Calibration measure
First buffer pH 7
Press <OK>...
Calibrating (12)
Please wait ...
pH-value buffer 1
7.00
Second buffer pH 4
Press <OK>. . .
Calibrating (10)
Please wait
pH-value buffer 2
4.00