MEASURING DEVICE AND METHOD FOR SENSING DIFFERENT GASES AND GAS CONCENTRATIONS

The invention relates to a measuring device for sensing different gases and gas concentrations, comprising an infrared radiation source, a measurement channel, which has an optical path and a gas interaction path, and radiation detectors arranged along the measurement channel. The invention further relates to a method that uses the measuring device. The problem of providing an optical measuring device that has a considerably improved detection limit and a compact and simple design and that can be economically produced is solved in the arrangement in that the optical path has at least one deflection point, wherein a first band-pass interference filter is arranged at a first deflection point and a first radiation detector is arranged after the band-pass interference filter. The problem is solved by means of a method having the following steps: measurement radiation is introduced into a measurement channel containing the gas to be measured, the measurement radiation hits a first band-pass interference filter arranged at a first deflection point, wherein only radiation of a wavelength defined by the first band-pass interference filter hits a radiation detector arranged after the band-pass interference filter, the radiation reflected at the band-pass interference filter is forwarded along the optical path in the measurement channel to a second radiation detector, and the gas concentrations measured by means of the radiation detectors are evaluated.