| 摘要 |
A method and an analyser for determining the concentration of NO in a breathing gas, also containing O2 with which NO reacts to form NO2, are described. The problem in determining the NO content of a breathing gas in a reliable fashion is solved by, in a first stage, increasing the pressure of the breathing gas for a predefined period of time so NO present in the breathing gas is almost completely converted into NO2, whereupon the concentration of NO2 is measured and the concentration of NO is determined from the measured concentration of NO2. An analyser (10) for carrying out the method comprises a first reciprocating pump (30) and a second reciprocating pump (36) which interact in compressing a sample of the breathing gas for a predefined period of time. The gas sample is then sent to a measurement chamber (46) in which the concentration of NO2 is measured. An analysis unit (52) controls the entire analyzer (10) and determines the NO concentration from the measured concentration of NO2. <IMAGE> |
