4
TROUBLESHOOTING
Problem
Cause
Solution
Meter not switching
on / No power
Discharged batteries
Charge batteries
Incorrect battery polarity
Check the polarity
Battery failure
Replace batteries with AA (R6) Rechargeable type
Power adapter failure
Check with other 5V USB power adapter (for
mobile)
Unstable reading, lack
of reading
Poor connection
Check sensor connection to the unit
Air bubble in the membrane cap
Check for air bubbles, refill electrolyte or replace the
membrane
DO sensor membrane contaminated / broken
Clean the sensor according to its manual or replace
the membrane
Anode or cathode is contaminated
Clean zinc anode with sandpaper. Clean silver
cathode, on top, only with smooth cloth!
Break in cable, connector or internally in
sensor
Check cable and connector, replace the sensor
DO sensor defective
Replace sensor
Meter is not
calibrating
Membrane polluted
Clean or replace the membrane
Membrane defective - broken
Replace membrane
Electrolyte used up
Refill electrolyte
Calibration mode not entered properly
Press and hold the CAL button till displaying Cal
symbol
Intermittent or no connection of DO sensor
Check sensor connection to the unit
Unable to calibrate to 100%
Clean, refill or replace the membrane
Stabilisation time not long enough
Wait longer for result stabilisation
DO sensor defective
Replace sensor
Result different than
expected
DO sensor not calibrated
Calibrate the sensor
Membrane polluted
Clean or replace the membrane
Electrolyte used up
Refill electrolyte
Calibration not correct
Make 2 points calibration
Reading stabilisation time to short
Longer wait for result stabilisation
0% DO concentration solution used up
Add sodium sulphite or prepare new solution
Wrong salinity value introduced
Delete or change introduced salinity value
Wrong air pressure value introduced
Delete or change introduced air pressure value
Stabilisation time not long enough
Wait longer for result stabilisation
DO sensor defective
Replace DO sensor
Result drifting down
Air consumption by sensor
Use stirrer or slowly move the sensor in the vessel
Result drifting up
To intensive stirring, sensor close to air
source
Slow down stirring, place the sensor in a different
place
Temp. value incorrect
or
symbol
displayed
Temperature sensor not connected or poor
connection
Connect the temp. sensor / check the connection
Breakage in temp sensor cable or connector /
defective sensor
Check connection / replace sensor
Information: oxygen
sensor calibration
readout error!
DO sensor calibration data loss
Recalibrate the DO sensor
If the situation appears after each switching
on
Contact distributor or service agent
Information:
Manufacturer's
settings readout error!
Internal hardware or software problem /
Losing factory settings
Contact distributor or service agent
