Rank: Advanced Member Groups: Member
Joined: 7/4/2011 Posts: 1,288 Location: United Kingdom
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Nem, breathing pure oxygen through a mask at normal atmospheric pressure will fully saturate the blood and tissues. Doing it in a chamber just speeds the saturation process up.. Think of it this way - air is roughly 79% nitrogen and 21% oxygen. So in normal breathing a considerable amount of nitrogen is in the blood plasma, tissues, organs and bones. When you breath pure Oxygen the nitrogen slowly get replaced with Oxygen and the nitrogen slowly comes out of all the relevant body parts. Not sure how long it takes but it's slow at 1 atmospheric pressure. Nitrogen gets into the tissues by a number of routes including air swallowing and lung exchange. Blood itself is saturated very quickly but replacing all the other gases in tissues etc takes time.
The bends are when extra gas bubbles out of the blood and tissues when you change depth, coming up, from a dive under pressure.Bit like a bottle of soda po. When the bottle is kept still you don't see anything but just shake it and the extra CO2 bubbles out.
wITH any type of mask you should ensure that your exhaled breath containing CO" is washed out of the masked by the pressure of the incoming Oxygen. That means there will always be Oxygen leaking from around the mask. Be careful, and ensure no naked flame, no grease or oil is on the mask etc. Warning pure oxygen should be handled with extreme caution. In contact with oil/grease it may exploded or catch fire and if released into confined spaces can cause spontaneous combustion. When setting up any O2 cylinders have a look at the thread connectors and make sure they are clean from oil, grease dirt etc. When attaching a pressure guage and when first opening the gauge to check pressure do NOT look at the gauge directly but from the side. Gauges have exploded in the past and the glass front will shoot off at extreme speed. Have a fire extinguisher handy
Remember pure Oxygen killed those three guys in that NASA space capsule prior to launching, due to an electrical fault in pure oxygen causinga flash fire.
Incidently if you uses google look for Bibs masks for DDC's or dive chambers as that is the sort of masks we use. It has a O2 input line and an exhalation line or it can be used without the exhalation line as the mask has one way rubber exhaust valves to get rid of the CO2.
Into the heart, an air that kills, from yon far country blows. What are those blue remembered hills, what sphires what farms are those. That is the land of lost content,I see it shining plain, The happy highways where I went and cannot come again
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