Patent ID: 7705991

Claim:
A gas measuring apparatus for measuring a gas sample of inhalation anesthetics, carbon dioxide and nitrous oxide, the apparatus comprising: a radiation source for emitting radiation in first and second spectral ranges (Δλ 1 , Δλ 2 ); said radiation source being a component comprising: a radiator which is modulated at a frequency (f 1 ); and, a quartz glass envelope defining a broadband radiator and being mounted over said radiator; a measuring gas cuvette for accommodating the gas sample to be examined; a mirror assembly including: first and second reflecting mirrors disposed at a distance from each other; and, means for changing said distance between said mirrors; said mirror assembly being configured on the basis of an electrically tunable Fabry Perot interferometer which provides transmissions corresponding to said first and second spectral ranges (Δλ 1 , Δλ 2 ); a detector element for evaluating said first and second spectral ranges (Δλ 1 , Δλ 2 ); a drive unit connected to said mirror assembly for presetting a dynamic range with a frequency (f 2 ) for changing said distance so as to permit a first spectral range (Δλ 1 ) to be detected in a transmission range of between approximately 3.5 micrometers and 4.5 micrometers and a second spectral range (Δλ 2 ) to be detected in a transmission range of between approximately 8 micrometers and 12 micrometers; measuring signals (S 1 , S 2 ) being assigned to said spectral ranges (Δλ 1 , Δλ 2 ), respectively; and, an evaluation unit for separating said measuring signals (S 1 , S 2 ) assigned to said spectral ranges (Δλ 1 , Δλ 2 ).