wtw Multi 350i, Operating Manual

Page: 88 / 108

What to do if... Multi 350i
86
6.3 DO measurement
DO sensor was not
recognized
Error message OFL
Error message, Error
(invalid calibration)
Error message, LEAK
Measured value flashes
for a long time
(No stable measured
value)
Measured value too low
Cause Remedy
– Sensor not connected – Connect sensor
– Cable broken – Replace sensor
Cause Remedy
– Measuring range exceeded – not possible
Cause Remedy
DO sensor:
– Electrolyte solution depleted – Regenerate sensor
– Membrane contaminated – Clean membrane
– Electrode system poisoned – Regenerate sensor
Cause Remedy
DO sensor:
– Membrane damaged – Exchange the membrane cap
– Membrane head screwed on
not tight enough
– Screw membrane head tight
Cause Remedy
DO sensor:
– Membrane contaminated – Clean membrane
Cause Remedy
DO sensor:
– Insufficient flow – Provide flow to the sensor