Industrial control sensors, namely, optical, electronic, optoelectronic, photoelectric apparatus and systems for analysis and process measuring technology; Transmissiometers, namely, opacity monitors and dust monitors; Scattered light meters; Spectrometers; Photometers; Residual gas analyzers; Emission measuring, process analysis, process control, identification and data transmission apparatus with an electronic and/or optoelectronic base, namely, dust monitors based on transmission light, sc...