TERMINATOR said:
No such thing as hypobaric chamber...they are hypoxic chambers, which work on a completely different principle.
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Are you trying to split hair? Is Split is Valjavec's country, think not, must be in Croatia.
Anyway you can reduce the available oxygen by reducing the pressure, which admittedly is technically difficult, or by increasing the %age of nitrogen in the air, ie displacing the oxygen.
If you reduce the pressure without changing the 79/21 proportions of normal air for nitrogen/oxygen, you have a truly
hypobaric chamber. Presumably you could do it on the same principle as the Gamow hyperbaric chambers without escalating towards horrendous costs.
If you reduce the proportion of oxygen in the air, you have a hypoxic chamber/tent, which is obviously less oppressive (than a Gamow chamber) and technically easier to construct, hence cheaper.
The latter technical solution is presumably what people slightly improperly call hypobaric chambers/tents. When I read
hypobaric in this context, I understand
hypobaric equivalent