Troubleshooting
General troubleshooting
Problem Probable cause Resolution
Excessive time for
stabilization or no
stabilization during
calibration in air.
The sample temperature is very different
from the ambient temperature, e.g. 6 °C
(43 °F) in water and 35 °C (95 °F) in air will
cause a measurement drift.
Do not wait till the sensor temperature
equals the external temperature (use
temperature compensation).
There is an electrolyte leak through the
membrane. The current is too high because
of an excessive penetration of oxygen.
Change the membrane.
There is pollution of the electrolyte due to a
loose filling screw.
Change the electrolyte. Check there is a
gasket in place and tighten the screw using
a screwdriver but without using excessive
force.
The electrode is not correctly mounted in
the sensor body causing an excessive gap
between the membrane and the cathode.
Tighten the electrode holding nut.
The membrane is incorrectly installed
causing a risk of electrolyte pollution.
Change the electrolyte and reinstall the
membrane onto the sensor body as far as it
will go finger tight.
Lack of humidity due to high temperature.
Use a calibration cap (see Replacement
parts and accessories on page 19).
There is water or humidity in the sensor
cable connector.
Dry the sensor cable connector inside and
out, and install finger tight.
The gold surface is scratched or damaged. Change the electrode.
Sludge or particles on the cathode.
Clean the cathode with a soft and
absorbent tissue. Rinse the membrane.
Cable or connections damaged when the
sensor has been removed.
Check the sensor connection to the
controller module. If correct check the
connections to the sensor cable connector.
The sensor is incorrectly positioned. The
electrolyte has leaked and air bubbles have
entered the cathode.
Put the sensor in the correct position, head
down.
No significant
current increase
when the sensor is
in the air for the
calibration.
There is pollution of the electrolyte due to a
loose filling screw.
Change the electrolyte. Check there is a
gasket in place and tighten the screw using
a screwdriver but without using excessive
force. Check the sensor is not damaged.
There is pollution of the electrolyte due to a
leaking membrane.
Change the electrolyte and the membrane.
The membrane is torn. Change the membrane.
The electrode is not correctly mounted in
the sensor body causing an excessive gap
between the membrane and the cathode.
Tighten the electrode holding nut.
Cable or connections damaged when the
sensor has been removed.
Check the connection to the controller
module. If correct check the connections to
the sensor cable connector.
The membrane is worn. Change the membrane.
There is a dark green deposit of silver
bromide (AgBr) on the silver tube.
Polish the tube with a soft abrasive (N°
400 to 600) and replace the membrane.
16 English