wtw Multi 9310 - Dissolved Oxygen Issues

Multi 9310 What to do if...
ba75937e03 12/2011 89
No stable measured
value
Obviously incorrect
measured values
14.2 Dissolved oxygen
Error message,
OFL, UFL
The measured value is outside the measuring range.
Cause Remedy
IDS pH sensor:
– Junction contaminated – Clean junction
– Membrane contaminated – Clean membrane
Test sample:
– pH value not stable – Measure with air excluded if neces-
sary
– Temperature not stable – Adjust temperature if necessary
IDS pH sensor + test sample:
– Conductivity too low – Use suitable IDS pH sensor
– Temperature too high – Use suitable IDS pH sensor
– Organic liquids – Use suitable IDS pH sensor
Cause Remedy
IDS pH sensor:
– IDS pH sensor unsuitable – Use suitable IDS sensor
– Temperature difference
between buffer and test sample
too great
– Adjust temperature of buffer or sam-
ple solutions
– Measurement procedure not
suitable
– Follow special procedure
More information and instructions on cleaning and exchange of
sensors are given in the documentation of your sensor.