user manual: pSCR is not driven from back gas by default

Generalize the wording. pSCRs are typically configured with a swichblock,
allowing insertion a any gas in the unit, equivalently with a gas change
on open circuit.

Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>
This commit is contained in:
Jan Mulder 2017-03-06 10:53:24 +01:00 committed by Dirk Hohndel
parent 0398af341d
commit acb38c9e00

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@ -1954,11 +1954,11 @@ image::images/sidemount1.jpg["FIGURE: Sidemount profile",align="center"]
Passive semi-closed rebreathers (pSCR) are a technical advance in diving equipment that
recirculates the breathing gas a diver uses, while removing carbon dioxide from
the exhaled gas. While a small amount (typically a tenth) of the exhaled breathing gas is released into the water,
a small amount of fresh gas is released from the back gas cylinder.
a small amount of fresh gas is released from the driving gas cylinder.
A diver using a single cylinder of breathing gas can therefore dive for much longer periods than
using a recreational open-circuit configuration. With pSCR equipment, a very small amount of breathing
gas is released every time the diver inhales. With active SCR (aSCR) equipment, in contrast, a small amount of
breathing gas is released continuously from the back cylinder.
breathing gas is released continuously from the driving cylinder.
To log pSCR dives, no special procedures are required. Use the normal steps outlined above:
@ -1970,7 +1970,7 @@ To log pSCR dives, no special procedures are required. Use the normal steps outl
If a pSCR _Dive Mode_ has been selected, the dive ceiling for that is adjusted for the oxygen
drop across the mouthpiece, which often requires longer decompression periods. Below is a dive profile
of a pSCR dive using EAN36 on the back cylinder and oxygen for decompression. Note that this dive lasted
of a pSCR dive using EAN36 as bottom gas and oxygen for decompression. Note that this dive lasted
over two hours.
image::images/pSCR_profile.jpg["FIGURE: pSCR profile",align="center"]