Parr Instrument 6200 - Manual (Page 32)

33
6200
Calorimeter Operating Instruction Manual
Corrosive
Samples
5
The 1108 Oxygen Bomb is made
of a corrosion resistant alloy
designed to withstand the corrosive
mixture of sulfuric and nitric acids
produced in normal fuel testing
operations. Samples containing chlorine
and particular samples containing more
than 20 mg of chlorine samples with
high sulfur contents will greatly
accelerate corrosion of the bomb. An
alternate 1108CL Bomb is available
constructed of an alloy selected to
specifically resist the corrosive effects of
samples with high chlorine or chloride.
While no material will offer complete
corrosion resistance to these samples, the
1108CL Bomb offers significantly enhanced
corrosion resistance for this service.
The 1108 and 1108CL Bombs used
in the 6200 Calorimeter have been
designed to provide highly automated
testing of routine samples. Materials
which release large volumes of gas which
detonate with explosive force or burn with
unusually high energy levels, should not be
tested with these bombs.
Rather, they should be tested in a model
1104 High Pressure Oxygen Bomb
designed specifically for these types of
samples
.
Volatile samples can be handled
in a Parr 43A6 Platinum Capsule with
a spun rim, or in a Parr 43AS Alloy
Capsule which has a sturdy wall with
a flat top rim. These holders can be sealed
with a disc of plastic adhesive tape
prepared by stretching tape across the top
of the cup and trimming the excess with a
sharp knife. The seal obtained after
pressing this disc firmly against the rim of
the cup with a flat blade will be adequate for
most volatile samples.
The tape used for
this purpose should be free of chlorine and
as low in sulfur as possible. Borden Mystic
Tape, No. M-169-C or 3M Transparent
Tape, No. 610, are recommended for this
purpose. The 3M Transparent Tape can be
ordered through Parr, Part No. 517A.
The weight of the tape disc must be
determined separately and a correction
applied for any elements in the tape which
might interfere with the
determination. This can be done by running
a blank test with tape alone using a sample
weighing 1.0 gram. The compensation for
heat of tape may be done through the spike
option; see Spike Controls, Heat of
Combustion of Spike. The heat of
combustion of the 517A tape is
approximately 6300 cal/gram.
Note:
Tape should always be stored in a
sealed container to minimize changes in
its moisture and solvent content
.
Explosives
and High
Energy
Fuels
Volatile
Sample
Holders
Figure 5-7
Combustion Capsule
with Adhesive Tape Seal
5-7