Maintenance
29
Symptoms
Problems
Solution
Readings fl uctuate up
and down (noise).
DO: DO probe electrolyte
contains entrapped gas.
Remove cap. Refi ll, tap and reinstall.
The display shows DO
reading blinking.
Out of range in DO scale.
Verify area of cathode is free of
bubbles inside cap. Verify solution
movement past membrane. Remove
cap, inspect and clean if necessary.
Install new cap, fresh electrolyte with
no bubbles, permit longer polarization.
Stir or increase fl ow rate.
The meter does not
measure temperature.
“----” is displayed on
second LCD line.
Broken temperature
sensor.
Replace the probe.
At startup the meter
displays all LCD tags
permanently.
One of the keys is stuck.
Check the keyboard or contact your
local Hanna Offi
ce.
CAL “Prod” message at
startup.
Instrument was not
factory calibrated or lost
factory calibration.
Contact Hanna Technical Support for
help.
Troubleshooting
Guide
Summary of Contents for edge DO
Page 1: ...DO...