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 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.