Table of Contents
Advertisement
.ﻣراﺟﻌﮫ ﻓرﻣﺎﯾﯾدWWW.ELM-FAN.IRﺑرای داﻧﻠود ﻣوارد ﺑﯾﺷﺗر ﺑﮫ ﺳﺎﯾت
Description
Operating principle
In the off position, the handwheel 1 engages at the »0«
setting. fresh gas flows from the Vapor inlet 2 through the
ON/OFF switch 3 directly to the Vapor outlet 4.
Vapor's vaporising chamber is then completely shut off
from the gas flow and its inlet and outlet are short-
circuited.
A small bleed hole connects the vaporising chamber to
the atmosphere to prevent any build-up of pressure from
the vapour pressure of the anaesthetic agent. It also
guards against any anaesthetic agent getting into the
fresh gas flow via possible leakage points without being
noticed. During anaesthesia the Vapor can only be filled
in this unpressurised condition.
When the concentration is set, the fresh gas flows into
the vaporising chamber via the ON/OFF switch 3
connected to the handwheel 1.
Depending on the setting on flow control cone 5,
saturated vapour is added to the fresh gas and some of
the fresh gas flows into the vaporising chamber 6 and
becomes saturated with anaesthetic agent. The
remaining fresh gas is routed past the vaporising
chamber 6 through a bypass 7. The two flows are mixed
and routed to the Vapor outlet 4. The desired
concentration results from the proportioning of the two
gas streams.
The proportioning of the two gas streams is also
influenced by the temperature compensator 8, which
makes use of the thermal expansion characteristics of
two different materials to expand or contract the bypass
7, depending on the temperature. This process compen-
sates for the effect of temperature on the saturation
concentration of the anaesthetic agent.
The pressure compensation labyrinth 9 effectively
reduces any pumping effect, see page 37 (influence in
fluctuations in pressure).
To provide protection against excessive pressure, as, for
instance, from a kinked fresh gas hose, the Vapor has a
pressure relief valve in the ON/OFF switch 3 which
releases fresh gas into the atmosphere in case of high
pressures.
When the Vapor commences operation after a break of
more than 2 hours, the concentration delivered will be
higher than the set value for several seconds, but it will
then quickly drop back to the value desired. This effect is
the result of anaesthetic vapour diffusing into cavities in
the Vapor and then being flushed out when the Vapor is
switched on.
This briefly-increased concentration spreads into the
hoses and breathing system and, since it is thus
dispersed in a large volume, no significant increase in
anaesthetic agent concentration will reach the patient.
To download more items, go to ELM-FAN.IR
3
2
3
1
2
9
5
6
Description
Operating principle
1
4
4
8
7
8
31
Advertisement
Table of Contents
