Cleaning The Platinum Anode And Sensor Ceramic; Reassembly And Refitting - ABB Navigator 550 Operating Instructions Manual

Navigator 500
Hydrazine analyzer

8.4.3 Cleaning the platinum anode and sensor ceramic

Warning. Sodium Hydroxide is extremely caustic and must
be handled with great care. Wear gloves and eye protection.
1. Switch off sample flow to the wet-section.
2. Refer to Section 8.4.2, page 58, steps 4 to 7.

8.4.4 Reassembly and refitting

Referring to Fig. 8.6:
1. Carefully insert the platinum electrode into the ceramic
tube, taking care not to damage the electrode or the
electrical connection. Refit sleeve
B
knurled nut .
Ensure the O-ring is in good condition and located
correctly.
2. Carefully slide outer jacket
assembly.
3. Fill the hydrazine sensor assembly with fresh gel as
follows:
a. Holding the black closure cap tightly in place on the
filling syringe, snap the syringe plunger into position
and remove the black closure cap.
b. Slowly inject the filling gel through the lower hole in the
outer jacket until it reaches the top hole.
c. Remove the syringe and replace its closure cap.
d. Refit lower 10-32 UNF blanking plug
e. Refit upper 10-32 UNF blanking plug
4. Push the hydrazine sensor assembly into clip
sub-panel, ensuring outlet tube
H
above drain tundish
5. Reconnect the inlet tube to inlet nipple
Note. Hold the hydrazine sensor firmly at the top so that
the centre portion is not pushed out when the tube is
connected.
6. Reconnect the hydrazine
L
temperature sensor
7. Fill the reagent and calibration solution containers with
their respective solutions.
Warning. The sample is dosed with sodium hydroxide
and the concentration, although small at first, increases if
any spillage is left to evaporate. Dispose of the outflow
safely.
8. Open the sample isolating valve upstream of the
wet-section and adjust the sample flow rate until sample is
overflowing from the constant-head unit but not from the
emergency overflow.
OI/AHM550–EN Rev. A
A
and secure with
C
onto the hydrazine sensor
D
.
E
.
F
on the
G
is positioned directly
.
J
.
K
sensor (red)
(blue) electrical connectors.
9. Ensure that the sample is flowing through the hydrazine
sensor at the correct rate – refer to Section 3.1.1, page 8.
10. Close and lock the wet-section door.
11. Perform a calibration sequence – refer to Section 5,
page 23.
C
L
Blue
and
J
Fig. 8.6 Hydrazine sensor reassembly and fitting
B
A
O-ring
E
D
K
Red
H
G
F
59