IKA AOD 1.1 Mode D'emploi page 14

A new o-ring (item 7) should be used when the new
electrode is inserted.
Information on how to replace the
0-ring is provided further on in
this chapter. Make certain
that there are no dirt par-
ticles in the cover when
reasembling the unit.
Use a paper towel
to clean the sea-
8
ling surfaces.
Installation is
9
performed in
the reverse
order.
• Put the
rate insula-
ting bushing
(item 8 and
13) and the
bearing bus-
hing (item 9)
on to ignition
electrode.
• Insert
the new ignition electrode contained in the set of electrodes with
deflector (item 2002) into the cover.
• The hexagonal nut (item 11) should only be slightly tightened
with the spanner.
A leak test should be performed after assembly of the decom-
position vessel has been completed.
• Fill the decomposition vessel with oxygen. Use the C 48
oxygen station in order to do so.
• Hold the decomposition vessel with the cover upside down
in a vessel that is completely filled with water.
Be careful to only immerse only half of the decomposition vessel
at most.
14
31
11
7
13
11
12
11
11
• Check the decomposition vessel for escaping bubbles of
oxygen.
The leak test does not replace pressure testing !
Oxygen valve maintenance
The oxygen valve is used to fill and emptycthe decomposition
vessel. It is a non-returnable valve that only closes when the
decomposition vessel is full with oxygen.
The ignition electrode (item 5) serves at the same time as a valve
piston. The sealing surface is in the cover of the decomposition
vessel. The O-ring sealing wears through use and because of
aggressive combustion gases, which means that the decompo-
sition vessel may not be tight.
Check the sealings for wear in accordance with regular inter-
vals stipulated by the safety provisions. If the decompositi-
on leaks during combustion in the calorimeter the escaping
oxygen may damage the decomposition vessel and the calo-
rimeter.
• In order to replace the O-ring the ignition electrode must be
removed from the cover as described.
• Remove the O-ring (item 7) by first pulling the bearing bus-
hing (item 9) off of the ignition electrode and then removing the
O-ring.
• Place the new O-ring from the set of O-rings onto the igniti-
on electrode (item 5) from above and then push the bearing bus-
hing (item 9) until it again reaches the ignition electrode.
Make certain that the O-ring does not become damaged by
sharp edges.
After installation of the ignition electrode the bearing bushing is
teightened with the hexagonal nut (item 11) in order to prevent
it from slipping out of place.