wtw ConOx, Operating Manual

Page: 18 / 24

What to do if... ConOx
42 ba75383e04 04/2009
6 What to do if...
6.1 Error symptoms of DO measurement
6.2 Error symptoms of conductivity measurement
Error symptom Cause Remedy
The sensor is in the air
and the display shows
0.0 mg/l or 0 % O
2
– No connection between
measuring instrument and sensor
– Cable defective
– No electrolyte in the membrane
cap
– Check connection between
measuring instrument and sensor
– Replace and refill the membrane
cap (see section 5.3)
The sensor cannot be
calibrated – Contaminated membrane cap
– Electrolyte depleted – Replace and refill the membrane
cap (see section 5.3)
Subsequently, wait for 30 to
50 min and recalibrate.
The sensor still cannot
be calibrated after
changing the electrolyte
and membrane cap – Contaminated electrodes or
sensor toxification
– membrane cap not screwed on
tight enough
– Clean the electrodes (see
section 5.4)
– Screw membrane cap tighter
Incorrect temperature
display – The temperature sensor of the
conductivity basic module was not
immersed deep enough in the
measuring solution
– Temperature sensor defective
– Observe the minimum immersion
depth
– Return the sensor
Mechanical damage to
the sensor – Return the sensor
Error symptom Cause Remedy
No temperature or con-
ductivity display – No connection between
measuring instrument and sensor
– Cable defective
– Check connection between
measuring instrument and sensor
Measurement delivers
implausible conductivity
values – Incorrect cell constant adjusted at
the measuring instrument
– Measuring range exceeded
– Contamination in the area of the
electrodes
– Electrodes damaged
– Check / correct the cell constant
– Observe the application range
– Clean the sensor (see
section 5.2).
– Return the sensor
Incorrect temperature
display – The temperature sensor was not
immersed deep enough in the
measuring solution
– Temperature sensor defective
– Observe the minimum immersion
depth
– Return the sensor