Parr Instrument 1104 - Manual (Page 6)

1104 Oxygen Combustion Vessel
P a r r I n s t r u m e n t C o m p a n y 6
Preparing the Fuse When the Combustion
Cage is Not Used (Continued)
Set the bomb head on the support stand (P/N A38A)
and attach one end of a 10 cm length of fuse wire
between the two electrodes.
Fasten one end of the wire to the loop electrode
(steps a thru d) then attach the other end to the
straight electrode (steps e thru h). Pull the loop
downward to tighten the connections then bend the
wire upward (step i). Place the capsule in the loop
holder and bend the wire down to the sample (step
j).
Note: Do not submerge the wire in liquid or
powder samples; better combustion will be ob-
tained if the loop of the fuse is set slightly above
the surface. When using a sample that has been
pressed into a pellet, bend the wire so that the
loop is positioned about a centimeter above the
sample.
Closing the Bomb
Close the 1104 Oxygen Combustion Vessel by slid-
ing the head into the cylinder and pushing it gently
until the head is pressed against the inside ledge
of the cylinder. Confirm that the compression ring
(P/N 212A2) is in place above the head. Ensure that
all the compression screws in the screw cap do not
protrude through the underside of the cap. Attach
the screw cap and turn it down by hand as far as it
will go. Progressively tighten the circle of compres-
sion screws in a star pattern until each bears firmly
against the compression ring.
Note: Do not use the spanner wrench (P/N 219A)
to seal the bomb. Extreme force is not required
when tightening the cap. It is important that the
screws be tightened uniformly so that the clos-
ing forces are evenly distributed.
Filling the Bomb Using a Calorimeter
The oxygen inlet connection on the 1104 Oxygen
Combustion Vessel differs from the connection used
on the 1108 Oxygen Combustion Vessel in that it is
Attaching Fuse Wire with Loop Electrode