54 of 66 Maintenance and Troubleshooting - 3654 Portable H2/N2 Analyzer
Operator Manual
ORBISPHERE
Table 6-2: Troubleshooting Table
Symptom Cause Possible Solution
Unstable
measurement
Degassing Adjust sample flow rate
Flow chamber and/or membrane not clean Clean system
Sensor’s membrane not tight smooth and
wrinkle free
Replace membrane and
recalibrate
Leaking solenoid valve
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 Ultra
representative.
An external power supply is used but the
power supply is not clean Switch to battery power
Low readings
Sample flow rate too low Check flow rate
Degassing Adjust forcing gas and/or sample
flow rate
Membrane is not at sample temperature
Allow sample to flow past the
membrane to make sure the
membrane is at sample
temperature before making
measurements
Membrane not clean Clean system
Incorrect solubility curve Change solubility
Incorrect calibration Recalibrate
High readings
Membrane is not at sample temperature
Allow sample to flow past the
membrane to make sure the
membrane is at sample
temperature before making
measurements
Incorrect solubility curve Change solubility
Incorrect calibration Recalibrate