Troubleshooting Table - Hach ORBISPHERE 3658 Manuel D'utilisation Simplifié

8.2.4 Troubleshooting table

Symptom
Unstable measurement
Low readings
High readings
26 English
Cause
Degassing
Flow chamber and/or
membrane not clean
Sensor's membrane not tight
smooth and wrinkle free
Leaking solenoid valve
An external power supply is
used but the power supply is
not clean
Sample flow rate too low
Degassing
Membrane is not at sample
temperature
Membrane not clean
Incorrect solubility curve
Incorrect calibration
Membrane is not at sample
temperature
Incorrect solubility curve
Incorrect calibration
Possible Solution
Adjust sample flow rate
Clean system
Replace membrane and recalibrate
No gas bubbles should escape from the
purge gas outlet during measurement. If
the solenoid leaks (more than 1 bubble in
15 seconds) contact your Hach Lange
representative
Switch to battery power
Check flow rate
Adjust forcing gas and/or sample flow
rate
Allow sample to flow past the membrane
to make sure the membrane is at sample
temperature before making
measurements
Clean system
Change solubility
Recalibrate
Allow sample to flow past the membrane
to make sure the membrane is at sample
temperature before making
measurements
Change solubility
Recalibrate