Continuous Purge; Troubleshooting Table - Hach ORBISPHERE 3658 Manual Básico Del Usuario

Message Meaning
During start-up, this message indicates the instrument cannot complete the start-up tests
successfully. Refer to
Hach Lange service representative for assistance.
Err
During calibration, this message indicates that the partial pressure of gas is below the acceptable
range (<5 mbar), or that you have pressed a wrong key. Refer to
Bat The batteries charge are too low for a correct operation of the instrument. Replace the batteries.

Continuous purge

It may be useful, particularly when seeing a [Pur] error message on your display, to view the purge
voltage of the TC sensor in a continuous purge mode. In this mode, there is no purge/measurement
cycle, as the purge gas is flowing through the sensor continuously.
To start continuous purge mode, put the instrument into standby, then hold down the Down Arrow
button while switching the instrument back on again. The instrument displays [Pur], followed by the
purge gas voltage. At 20-25°C, this voltage should be about 1.0V (± 200 mVolt) for CO
measurements.
To exit from continuous purge mode, put the instrument in standby, then switch back on again
without holding any keys.

Troubleshooting table

Symptom
Unstable measurement
Low readings
High readings
Table 2 Diagnostic messages (continued)
Taking measurements
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
on page 10. If the problem persists, contact your local
Sensor 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
on page 17.
2
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