smoke hood

[Torstennnn]

jar fcl test is bothering me with questions about smoke hoods -
havin heard they'd supply oxygen on demand, i wonder if their answer
"sh delivers o2 in continous flow" is correct

[Avtrician]

On demand means, that O2 is supplied when you take a breath, and stops as you breath out. bit like a scuba diving regulator

[Torstennnn]

that much is clear..
but what's true for the smoke hoods your ac is provided with?
O2 on demand or continously?

[apaddyinuk]

I know that the O2 masks provided in the flight deck are on demand. However the smoke HOODS provided by my carrier (Draeger) are no on demand and once the O2 starts generating it lasts for only about 15 minutes regardless of whether it is been worn or not!

[northern-light]

PBE's or smoke hoods have a buildt-in generator which produces O2 in a "solid state" and once activated will continue to provide oxygen for about 15 minutes whether you need it or not... (similar to passenger cabin o2 masks on most aircrafts)

Portable oxygen bottles and the supply in the flight deck are "gaseous", and will supply oxygen only on demand.

[Torstennnn]

so jar fcl was right,
thanx to everybody contributing

[Whiskey Zulu]

Correct about smokehoods providing continuous oxygen, though not all of them provide chemically produced O2. L'air lequide smokehoods provide gaseous O2.
And again, correct about flight deck oxygen providing O2 on demand (unless on emergency - constant flow)
Incorrect about portable oxygen bottles though. They provide constant flow, gaseous oxygen, not on demand oxygen. Well the only ones I have ever seen do. Apart from the Zero 2 plus therapeutic oxygen bottles, which can provide oxygen via either setting.