wtw inoLab 740, Operating Manual

Page: 244 / 274

What to do if...
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14.5 Oxygen system messages
Measuring modules for the inoLab Level 3:
pH, BSB/BOD, pH/Oxi and Multi.
Error message
OFL
Error message
E3
Error message
E7
Cause Remedy
Display range exceeded
– Not connected – Connect the probe
– Cable broken – Replace probe
– Depleted – Replace probe
– Short-circuit between gold
and lead electrode
– Clean probe and
replace it if necessary
Cause Remedy
Invalid calibration
– Electrolyte solution
depleted
– Regenerate probe
– Membrane contaminated – Clean membrane
– Electrode system poisoned – Regenerate probe
– Worn out – Replace probe
– broken – Replace probe
Cause Remedy
Membrane damaged
– Membrane damaged – Regenerate probe
– Membrane head not
screwed on tight enough
– Screw membrane head
tight