Portable gas sensor based on spectral analysis

摘要

The invention relates to a gas-adapted sensor unit (1) for determining the presence of and evaluating the concentration of a gas or gas mixture that induces an anaesthetic and/or analgesic effect. Means are provided for comparing sensor or sensor-unit output signals and/or measurement values formed therefrom with pre-determined threshold values so as to enable an emergency-related alarm signal to be set via light generating devices (1b) in the case of excessively high measurement values. One or more circuits that form averages or that integrate instant measurement values associated with the sensor unit are adapted to establish, over a pre-determined long time duration, an environment-related value that corresponds to the time dependent values of the output signal. When the environment-related value (1a'') exceeds a pre-determined environment-related threshold value, there is generated an environment-related alarm signal through the medium of a further circuit and through the medium of a light generating device (1b). The sensor unit (1) has external measurements that conform to or are smaller than the measurements valid for a pocket-sized unit. The gas mixture passes a measuring cell adapted for spectral analysis, by convection.