Parr Instrument 6400 - Manual (Page 26)

6400
Calorimeter Instruction Manual
4-7
When superior corrosion resistance is needed, the Platinum Rhodium 43A5 Capsule is
required.
Test Process
Loading the sample
Prepare and weigh the sample to 0.0001g. Gently tap capsules that contain powdered
samples to compact the material. (Pellets are easier to handle than loose samples and
they burn slower in the bomb, thereby reducing the chances for incomplete combustion).
Carefully place the capsule into the capsule holder. A cotton thread (845DD2) is used
as an auxiliary fuse to ignite the sample. Remove any moisture from the heating wire
prior to attaching the cotton thread.
Figure 5 - Cotton Thread Assembly
Four inches of thread is recommended for this auxiliary thread which is looped over the
heating wire, doubled on itself, twisted to form a single strand and fed into the sample
cup to lay on the sample. When contact is made through the heating wire, the thread
will ignite, drop into the sample cup and ignite the sample. One spool of thread, part
number 845DD, is 563 yards. Part number 845DD2 contains approximately 1000 pieces
of thread pre-cut to 4 inches.
Closing the bomb
Care must be taken not to disturb the sample when moving the bomb head from the
support stand to the bomb cylinder in the calorimeter. Check the sealing ring to be sure
that it is in good condition and moisten it with a bit of water so that it will slide freely into
the cylinder.