Aztec 600 ISE ammonia and fluoride
Single-stream ion-selective analyzers
Appendix B – Troubleshooting
OI/AXM630–EN Rev. I
77
Appendix B – Troubleshooting
B.1 Analyzer Malfunction
In the majority of cases, problems experienced are associated
with the probe so check this first – see Appendix B.3. If the
problem remains, check the chemistry (see Appendix B.2) and
the liquid handling section as described below. Other faults, their
possible causes and suggested remedies are shown in Table
B.1 on page 78.
Check mechanical components that are involved with the liquid
handling systematically. For example, check pump and valves
for correct operation and tubing and tubing connections for
leaks or blockages that could change the chemical conditions
within the analyzer.
To minimize malfunctions, ensure the system is functioning
correctly. To check the integrity of the readings, ABB
recommended that the analyzer and the sampling system is
visually inspected on a regular basis as follows:
Check for leaks, particularly around the sample and drain
pipe connections.
Confirm sample flow by checking delivery to the constant
head unit and effluent from the drain.
Check the liquid flow over the probe membrane / sensing
surface.
Check liquid levels in the reagent and standard solution
containers.
Check for malfunction indications on the analyzer's
display.
B.2 Reagent and Standard Solutions
Any unpredictable problems may be due to the standard or
reagent solutions or their flow through the analyzer. If any doubts
exist regarding the integrity of these solutions, replace them with
freshly prepared solutions in the early stages of the fault-finding
process. Ensure that appropriate concentrations of the reagent
and standard solutions are used. When changing standard or
reagent solutions, replace the container also, removing the
empty / used one for thorough cleaning.
DO NOT
top-up
reagent and / or standard solutions.
B.3 Probe Malfunction
B.3.1 Ammonia Analyzer
In the event of an ammonia probe malfunction, check for
leakage past the membrane. This is indicated by the internal
filling solution – it incorporates a yellow-colored indicator that
changes to blue if the probe membrane, or membrane seal,
allows alkaline reagent to leak into the probe. If this has
occurred replace the membrane – see Section 13.4, page 68.
The solution keeps indefinitely.
B.3.2 Fluoride Analyzer
A noisy sensor output can be caused by excessive bubble
build-up on the sensing end of the fluoride probe.
