Simple on-line gas monitoring and analysis equipment for e.g. vehicle exhausts and chemical plant

摘要

Wave-guide connects directly to the gas line; there are no reduced-pressure systems extracting gases for analysis. The wave-guide is connected to one or more microwave and/or IR detector(s). An Independent claim is included for the corresponding analysis method. Preferred features: Wave-guide (6) and/or resonator provided, are at least partly ceramic with conductive surfaces, especially coated with noble metal. The wave-guide is open into the gas line (2), with no protective window. Both microwave and/or IR transmitters are provided. A temperature sensor is included. Wave-guide construction effects frequency filtering. A computer compares measured- with known, stored spectra for intensity and fit, determining mixture composition. At least two frequencies are used. Black body radiation is taken into account and evaluation takes place only at given frequencies. These frequencies are selected, such that spectral lines from two of the gases of interest do not superimpose.