Dräger Vapor 2000 - Dependencies of the Vapor 2000

5327.400 Vapor 2000 05/99 Function Description Page 6
For internal use only. Copyright reserved. GBF5327400T01.fm 28.08.01
3 Dependencies of the Vapor 2000
3.1 Dependency on temperature
The Vapor 2000 is temperature-compensated. As the temperature rises the saturation
concentration of the anaesthetic is automatically compensated by routing a large portion
of the gas flow through the vaporizer chamber bypass.
The linear expansion of the temperature compensator produces flow changes at the
vaporizer chamber bypass. The linear expansion does not correspond precisely to the
curvature of the vapour pressure curve over the entire temperature range. Consequently,
a slight dependency of the concentration delivered on the temperature remains.
The diagrams show the typical dependency in operation with air (2.5 L/min). At temperatures
outside this range the deviations increase in spite of compensation.
As the altitude increases the boiling point of the anaesthetic decreases:
Table 1: Boiling point of anaesthetic
Boiling point of anaesthetic in °C
Air pressure (hPa)/
Altitude (m)
1013 hPa/
0m
900 hPa/
1000 m
800 hPa/
2000 m
700 hPa/
3000 m
Halothane 50.2 46.8 43.4
1
1. Impermissible operating ranges
39.8
1
Enflurane 56.5 53.4 50.3 46.8
Isoflurane 48.5 45.4 42.2
1
38.9
1
Sevoflurane 58.6 53.4 52.1 48.7