Hd-Ph/P ( Calibration) - Etatron HD-PH Instrucciones

by the probe.
g. The function "ALL" (7) is an alarm that comes into operation whenever the mea-
sured pH value differs by more than two units from the set value. The alarm is
accompanied by the lighting up of the red LED and the closure of an NO/NC
(Normally Open / Normally Closed) contact on the output side, which can be
used to control external equipment. In this situation the pump will operate at
the maximum rate.
This metering pump is predisposed for LEVEL CONTROL. To this end it is suffi-
cient to connect the level probe (not included in the supply) to the pump by means
of the connector 10. Level control is an option that will bring the metering pump to
a halt whenever the level of the additive in the storage tank attains a minimum set
by the operator.
8.6 HD-PH/P
(
CALIBRATION
All the HD-PH/P pumps are calibrated at the works at a temperature of 20°C, so
that only small regulating adjustments are required on the occasion of installation.
These are due for the most part to the type of electrode used and the working tem-
perature prevailing in the plant, since especially the latter exerts a considerable
influence on the pH value. The temperature error can readily be compensated by
operating on the "temperature compensation trimmer" (5).
The regulators that render calibration possible are located on the front panel.
These operations become necessary at regular intervals because the electrodes not
only tend to change their physico-chemical composition in the course of time, but
will also modify their measuring efficacy.
When checking the curve, use two buffer solutions at pH 4 and pH 7 if you wish to
work in the acid range or, alternately, pH 9 and ph 7 if you wish to work in the alka-
line range.
We would therefore advise that the calibration curve be checked at least once a
month, going through the routine described below.
When checking the curve, use two buffer solutions at pH 4 and pH 7 if you wish to
work in the acid range or, alternately, pH 9 and pH 7 if you wish to work in the
alkaline range.
• Adjust temperature manual compensation trimmer "°C"(5) according installation
temperature.
• Dip the electrode into a pH 7 buffer solution for few seconds.
• Adjust "∆0" (17) trimmer until display shows pH 7.00.
• Dip the electrode into a pH 4 or pH 9 buffer solution for few seconds.
• Adjust "pH/mV" trimmer (16) until display shows pH value according to the
used solution.
)
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ENG