Aztec 600 ISE ammonia and fluoride
Single-stream ion-selective analyzers
13 Maintenance
68
OI/AXM630–EN Rev. I
10. Referring to Fig. 13.1:
a. Release catch
B
, push the liquid-handling section
panel rearwards into the enclosure and lock it into
position with catch
B
.
b. Close the liquid-handling section door and secure with
thumbscrews
A
.
11. Replace reagent tube in reagent bottle.
12. Prime and calibrate the analyzer – see Section 4.1,
13.4 Replacing Ammonia Probe Membrane
Referring to Fig. 13.4:
1. Unscrew end cap
A
from probe body
B
and allow filling
solution to drain.
2. Remove probe cap
C
.
3. Carefully unscrew glass electrode
D
from body.
4. Rinse the probe body with distilled or de-ionized water
and allow to drain.
5. Rinse the electrode with distilled or de-ionized water and
dry with a paper tissue.
6. Remove membrane sealing washer
E
and membrane
F
from end cap
A
and discard.
7. Replace probe body seal
G
with new item.
8. Insert new membrane
F
into end cap
A
and place new
membrane sealing washer
E
centrally upon it.
9. Screw electrode
D
into body
B
until the top of the
electrode is flush with the top of the probe body.
10. Note the number on the electrode cap
H
that is aligned
with the mark on the body. Unscrew the electrode 4 full
turns using the number and mark as reference.
11. Screw end cap
A
firmly onto body
B
; both body seal
G
and membrane sealing washer
E
must be under
compression but do not screw the end cap on so tightly
that membrane
F
distorts.
12. Hold the probe upright and inject the filling solution
provided through filling hole
J
. Fill the probe to a depth
of between 50 and 60 mm (1.96 and 2.36 in.), ensuring
that reference element
K
is immersed in the solution.
Wipe any excess filling solution from the body.
13. Tap the end of the probe with the finger to dislodge any air
bubbles trapped between the end of the glass electrode
and the membrane.
14. Screw electrode
D
down 4 turns until the number on
electrode cap
H
, noted at step 4 is again aligned with
the mark on the body (the top of the electrode should be
flush with the top of the probe body).
15. Screw electrode
D
down a further 1.0 ±0.1 turns. Check
that the tip of the electrode is pressing against the
membrane. If the electrode response is sluggish, the
electrode may be screwed down by a further 0.2 to 0.3
turns. DO NOT overtighten – this will puncture the
membrane.
16. Push probe cap
C
onto the top of the probe body so
that it covers filling hole
J
.
Fig. 13.3 Replacing the analyzer tubing
A
D
C
B
E
F
G
H
J
K
Note.
Mixer fitted to fluoride analyzers –
optional fitting on ammonia analyzers.
