Parr Instrument 6200 - Manual (Page 29)

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6200
Calorimeter Operating Instruction Manual
10. Remove all unburned pieces of fuse
wire from the bomb electrodes;
straighten them and measure their
combined length in centimeters.
Subtract this length from the initial
length of 10 centimeters and multiply
this burned length by 2.3 calories
per cm (for Parr 45C10 Fuse Wire)
to obtain the fuse correction. The
scale on the fuse wire card can be
used to obtain this value directly.
11. Titrate the bomb washings with a
standard sodium carbonate solution
using methyl orange, red or purple
indicator. A 0.0709N sodium
carbonate solution is recommended
for this titration to simplify the
calculation. This is prepared by
dissolving 3.76 grams of Na2CO3 in
the water and diluting to one liter.
NaOH or KOH solutions of the same
normality may be used.
12. Analyze the bomb washings to
determine the sulfur content of the
sample if it exceeds 0.1%.
Methods
for determining sulfur are discussed
in Operating Instructions No. 207M.
13. At the end of the testing period, turn
OFF the calorimeter at the power
switch.
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