Northern Meditec Crius V6, Руководство оператора

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7.4.3 Affecting factors of monitoring
Effects of atmospheric pressure
Use the percentage of the volume as the unit to reporte the gas concentration, at this time the
measurement results are not affected by atmospheric pressure. Concentration is defined as follows
：
%gas=Partial pressure of gas component/Total pressure of gas mixture*100.
The total pressure of the mixed gas using the cup pressure sensor of ISA gas analyzer tomeasure.
When the test result using partial pressure indicated that it is related with the current atmospheric
pressure , need to be calculated based on the actual atmospheric that the analyzer sent, the
following formula:
CO2
（
mmHg
）
=CO2 concentration×pressure from the ISA (kPa) ×(750/100).
For example
：
5.0Vol%Co2(101.3kPa)
，
according to the above method transfer
：
0.05×101.3×750/100=38 mmHg.
Effects of moisture
The partial pressure and the volume percentage of CO2
、
Nitrous oxide
、
O2 and Anesthetic depend
on water vapor content.Calibrate theO2 measurement will display 20.8Vol% at the actual ambient
temperature and humidity level, but not the actual partial pressure. 20.8Vol% O2 corresponding to
the actual O2 concentration in the room (water concentration 0.7Vol%) (e.g., at 101.3kPa,
corresponding to 25
℃
and 23% RH). When measuring CO2, Nitrous oxide and O2(for example,
all gas measured by the infrared pool) will always show the actual partial pressure in current
humidity level.
In patient’s alveolar, water vapor in respiratory gas at body temperature achieved saturated
(BTPS).
After collected and put the breathing gas to the sampling tube,before the gas enter ISA sidestream
monitor,it’s temperature turn to close to ambient temperature.When Nomoline sampling tube
remove all condensed water
，
the moisture will not enter ISA sidestream monitor.The relative
humidity of the collected gas is about 95%.
If you need Co2 value under BTPS, the formula as follow
：