Draw the test solution from the reservoir in the reaction
chamber by turning the burette stop cock 'H' to connect
the burette with the reaction chamber and then lowering
the leveling bottle. Squeeze the rubber pipe to expel all
the air and then close the stop cock, so that reaction chamber
and the inter-connecting rubber pipe are completely filled
with test solution.
The purging vessel (lute) is half filled with water and
the sample gas to be tested is allowed to bubble through
water to atmosphere. Fill the burette with fresh solution
by turning the stop cocks 'G' and 'H' to connect with the
purging vessel, so that, all the air gets expelled. Repeat
it till all the air bubbles are removed. When solution commences
to flow from the burette to glass tube, close the stop cock
'G' close the cock it and replace the leveling bottle in
the holder.
TEST PROCEDURE OXYGEN GAS NITROGEN GAS
ACETYLENE GAS PLANTS :
Open the stop cock 'G' adjust the gas flow and allow the
sample gas to babble through the purging vessel for one
or two minutes. Check that the burette and test connection
tubes are completely filled with solution. Turn the stop
cock open to the burette connection. Then slowly open the
cock 'H' and allow the oxygen to pass into the burette (not
to the reacting chamber), controlling the oxygen flow. When
the burette is filled below the bottom mark, close the stop
cocks 'H' & 'G'.
Adjust the level of the gas in the burette to the 100 cc mark by holding the leveling bottom at the level of the liquid in the burette and carefully open the cocks 'G' and 'H' to bubble through the purging vessel to atmosphere.
Pass the gas sample into the reaction chamber by turning the burette stop cock 'H' to connect with the reaction chamber and raising the leveling bottle. The sample should be passed between the burette and chamber several times.
On the first passage into the reaction chamber, the volumes
of gas sample are greatly diminished. The oxygen in the
sample reacts with the copper to form an oxide which dissolves
in the solution. After the first passage of the sample,
the volume diminution becomes progressively less until all
the oxygen gas has been absorbed by the copper and only the
uncreative impurities remain unabsorbed.
Transfer the unabsorbed gas from the reaction chamber to
the burette by the lowering the leveling bottle. Do it a
few times to ensure that gas bubbles are not trapped in
the tubing. When all the unabsorbed gas has been passed
into the burette and the leveling bottle and observe the
amount of unabsorbed gas which present the percentage of
impurity of the sample.
