The controller always shows a high
value, or the reading is unstable.
o Cable connection to the
electrode is damaged
o The electrode has an air
bubble in the membrane area.
o Electrode fault. The
connection cable is too long or
it is too near to sources of
electrical interference (motors,
etc.)
o Clean the contacts or replace
the cable.
o Hold the electrode in vertical
position, with the tip down.
o Shake it lightly until the
bubble moves up.
o Replace the electrode. Locate
the controller nearer to the
electrode.
Impossible calibration.
o Polluted or expired buffer
solution.
o Electrode membrane blocked.
o Electrode fault.
o Verify the buffer solution is
not expired or polluted.
o Check the membrane is not
damaged. Clean the electrode
with diluted acid in water,
shaking it lightly.
o Replace the electrode
Slow response of the electrode. o Electrode electrostatically
charged.
o Insufficient renovation of the
analysed water (no flow
through the sample point)
o During the calibration phase,
the electrodes should not be
dried with paper or cloth.
Clean it exclusively with water
and shake it lightly.
o Ensure that the tip of the
electrode is submerged in
water at the sample point, and
that no air bubbles are
present.
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