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Sorry Angelo you are right. I was doing it while bored and commuting on the train .... I missed a 10^3 factor in the number of moles ...

I am not sure .... what the tech people would do but :) According to this article Dissolved Oxygen - Environmental Measurement Systems the best we can think of extracting from water are about 14 mg/l of oxygen. As each reb diver knows we need about 1-3 l/min of oxygen in normal conditions...

Hello there, I have no prior knowledge or exchange of messages with the author. I even contributed my knowledge by PM (acknowledged by the OP in the thread) in order to avoid appearing as one trying to demolish a good piece for minor imprecisions or as a know it all. I consider those...

Agreed, that is why every few dives, I do one in which I select setpoint LOW .7 and then fly the machine at the usual 1.3 for a shallow 1.5 hours (shallow 30-40 mt). It gives you the sense of what to expect when going manual.

I tend to agree with you for the first, not for the second. Your figure would be the average breathing pressure; in the first case that would be ok because you are ascending. In the second case you are doing stops so you cannot apply the average pressure but you need to calculate the usage for...

I believe you are right. The article is perfect for the stated purpose. Good night

That is correct. An mCCR is limited to half the pressure of the sealed first stage intermediate pressure (the flow stops being sonic and you would loose mass rate )or worst case to the pressure of the sealed first stage (you loose ability of adding oxygen even manually). In an eCCR you always...

Sorry I took issue to sonic pressure waves, there is no wave and no pressure only a sonic flow. No. The number of moles is constant no matter what the ambient pressure does as long as it stays below half of the intermediate pressure of the firsta stage that in a mCCR is sealed and, therefore...

I said I would stop, he asked to explain ... I did.

Ok I'll bite .... The amount of oxygen that you add to the loop needs to be constant because, save the amount you vent to clear your mask or otherwise, you use up a constant amount: the metabolised amount. So no matter depth, you need to add the same amount of moles. The n in the PV=nRT...

I did say I would stop I will say only PV=nRT amount is n not V

Then I’ll stop.

No bone to pick or willing to nitpick but if you want to divulge you need to be precise and understandable. The bit I am questioning is: which means we need to add less oxygen into the loop This is incorrect the ‘trickle’ of oxygen is automatically limited based on the increase in water...

Hello Tony, I might have read it wrong but I beg to differ in acouple of point which are fundamental: 1st the constant mass flow orifice works by establishing a sonic flow in a convergent divergent orifice (there is a shock wave in the narrowest section) there are no sonic pressure waves ...

That’s exactly why I find it strange. In such situation the body goes in a body bag and carrier not a coffin.... a magistrate has to intervene and authorize any operation on the body. It cannot be moved without permission.

Yes, quite possibly. Not a good way of reporting news anyway ...

Would the water in the tower qualify? Just joking!

This is a work operation. I expect health and safety (or whatever the name of the agency is in USA) to get involved and slam the company.

It is a literal translation of a word ‘ricomposta’ which could be used as meaning to make a body ready for viewing. But also as little as closing eyes and mouth, and pose arms and legs. I found it quite strange in usage here. Nobody is allowed to interfere with a deceased until a magistrate has...

There is some traction on sodium hydroxide in medical applications: http://actamedicamarisiensis.ro/wp-content/uploads/2015/01/amma-2015-0023.pdf I would be a bit wary for underwater use, due to the high solubility in water and consequently the high risk of a caustic cocktail. This is obviously...