Dräger LAR 8000

40 Instructions for use | LAR 8000
en | Description
Oxygen is used in accordance with EN 12021. Fresh gas is supplied via a lung
demand valve so that bubble-free diving is possible. The relief valve must be
completely closed. Breathing gas only escapes from the breathing circuit when it
expands during rapid ascent and can no longer be released into the environment in
a controlled manner by the diver.
Fresh gas is added via the lung demand valve or the manual bypass. The feature is
switched on as soon as the rotary switch of the switch device is set to oxygen
operation mode (not for O
2 version) and the oxygen cylinder is open, regardless of
whether a mixed-gas cylinder is connected or not. If gas is required, the breathing
circuit is filled up via the lung demand valve.
The carbon dioxide (CO
2) exhaled by the diver is absorbed in the soda lime of the
CO
2 absorber.
Due to the purging process before use, the O
2 content in the breathing circuit
corresponds to pure oxygen. The maximum diving depth for oxygen operation
mode must always be related to the use of pure oxygen.
The consumption of oxygen in the breathing circuit is the direct consumption of
oxygen by the body and is therefore directly dependent on the diver's physical
exertion.
3.2.2 Oxygen operation mode functional diagram
After opening the oxygen cylinder, oxygen flows through the pressure reducer to the
switch device (not for O
2 version). When the rotary switch of the switch device (not
for O
2 version) is in a horizontal position and protrudes from the housing, the path
of the oxygen to the lung demand valve is released and at the same time the mixed
gas supply is shut off.
The lung demand valve automatically delivers fresh gas into the breathing bag. Via
the inhalation hose, the inhalation valve and the mouthpiece, the breathing gas
reaches the diver via the mouthpiece with the mouthpiece closure open.
The response threshold (opening pressure) of the lung demand valve can be
changed to 1 of 3 settings via a lever on the lung demand valve.
The exhaled gas is led through the mouthpiece, the exhalation valve, the exhalation
hose, and the exhalation bag into the CO
2 absorber. The breathing circuit in the
device closes with the gas flow of the scrubbed gas from the CO
2 absorber to the
inhalation bag. If necessary, fresh gas is supplied through the lung demand valve
into the inhalation bag.
If there is an increased need for fresh gas (e.g. submerging and flushing the circuit),
fresh gas can also be added to the circuit manually using the manual bypass on top
of the device. Overpressure in the breathing circuit can be released through the
relief valve connected to the exhalation bag.