Navigator 500
Sodium analyzer
8 Maintenance
60
OI/ASO550–EN Rev. G
8.2 Scheduled servicing
The following procedures are guides to the maintenance
requirements of the wet-section. The procedure chosen
depends on the particular installation and sample conditions.
8.2.1 Weekly
If the wet-section is running continuously at high concentrations
(>100 µg kg
-1
) perform a weekly single-point calibration – see
8.2.2 Monthly
1. Replace the bottle of reagent solution at regular intervals
(see Fig. 2.1, page 6 for bottle location). If ammonia is
being used, the level of solution should not be allowed to
fall by more than
1
/
4
. Discard the remaining reagent
solution (predominantly water).
2. Refill the reference electrodes using the solution supplied
with the electrode:
–
for versions
with
a reservoir, check the level in the
reference electrode reservoir and refill if below 10 mm
(0.4 in.) – refer to Section 4.1.2, page 20, for filling
instructions.
Referring to Fig. 8.1:
–
for versions
without
a reservoir, ensure the level of
solution in reference electrode
A
is above the flowcell
block
B
. Refill as required.
3. Check sodium concentration.
–
When the sodium concentration is above 1 µg kg
-1
,
perform a two-point calibration – see Section 5.5,
page 24; note the
Slope
value.
–
When the sodium concentration is below 1 µg kg
-1
,
apply the regeneration procedure automatically or
manually – see Section 8.3, page 61 (automatic) or
Section 8.4, page 63 (manual).
4. Perform a automatic or manual regeneration procedure:
–
to perform an automatic regeneration (available only if
optional regeneration hardware is fitted), refer to
Section 8.3, page 61
–
to perform a manual regeneration, refer to Section 8.4,
page 63
Note.
The frequency at which reagent needs to be
replaced is dependent on the ambient temperature and the
concentration of sodium being measured (for accurate low
sodium readings, the solution may require replacement
more frequently).
Fig. 8.1 Checking solution level,
non-reservoir wet-sections
Note.
It is important that this procedure is carried
out at regular 1-monthly intervals and that
the process is started as soon as a new
electrode is put into service.
It is extremely difficult to recover an ‘old’
electrode.
Note.
For information about the regeneration
solution, contact the local ABB representative.
