Comen C80 - Safety Alarm Information; ISA Sidestream Gas Analyzer Safety Warning Information

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pressure, will be displayed. 20.8 vol% of oxygen corresponds to the actual oxygen
concentration of indoor air (the water concentration is 0.7 vol%) (for example: at 1013 hPa,
corresponding to 25°C and 23% RH). The actual partial pressure at the current humidity level
will be displayed all the time when CO
2
, N
2
O, oxygen and anesthetic gases (all the gases
measured the infrared cell) are measured.
In the pulmonary alveoli of a patient, the water vapor in breathing gases become saturated at
the body temperature.
After breathing gases is collected and sent into the sampling tube, their temperature gets near
to the ambient temperature before they enter into the ISA sidestream gas analyzer. After
Nomoline has removed all the condensed water, water molecules will not enter into the ISA
sidestream gas analyzer. The relative humidity of all the gases collected is approximately
95%.
If you need the CO
2
value under BTPS, you can use the following equation:
Et CO
2
= Et CO
2
value [vol %] sent by the ISA
Pamb = Atmospheric pressure [kPa] sent by the ISA
3.8 = Typical partial pressure [kPa] of water vapor condensed between the patient’s circuit
and the ISA
Et CO
2
(BTPS) = Et CO
2
gas concentration [vol%] under BTPS
It is assumed that standard oxygen of indoor air has been used at a humidity level of 0.7 vol%
H2O
18.8 Safety Alarm Information
18.8.1 ISA Sidestream Gas Analyzer Safety Warning Information
Warning