GE Monitor UPC-900 Operating Instructions Manual page 98

7 Troubleshooting
7.1 Fault actions
Component Problem
UV measure- Low sensitivity
ment
Error in external chart
recorder
pH measurement
Component Problem
pH measure- No response to pH
ment changes
Small response to pH
changes
Slow pH response or cali-
bration impossible
pH values vary with varied
back-pressure
98
Corrective action
Aging lamp. Check the lamp and replace if neces-
•
sary
Wrong lamp position. Check that the lamp position
•
and the wavelength used (filter position) fit together.
Dirty on-line filter. Clean or replace the filter.
•
Check the chart recorder in accordance with its
•
manual.
Test the recorder function by selecting recorder
•
test according to Check recorder, on page 68.
Corrective action
Check that the electrode cable is connected prop-
•
erly to the rear of the module.
The electrode glass membrane may be cracked. If
•
so, replace the electrode.
Clean the pH electrode according to Section 6.3.4
•
Clean the pH electrode, on page 89 and recalibrate.
If the problem remains, replace the pH electrode.
•
Check the electrode glass membrane. If it is contam-
•
inated, clean the electrode following the instructions
in Section 6.3.4 Clean the pH electrode, on page 89.
If the membrane has dried out, the electrode may
•
be restored by soaking it in buffer overnight.
Clogged liquid junction. Refer to Section 6.3.4 Clean
•
the pH electrode, on page 89.
Replace the pH electrode.
Monitor UPC-900 Operating Instructions 29-0567-16 AB