FIELD: measurement technology. SUBSTANCE: gas analyzer has wideband ultraviolet or visible radiation source, unit for forming beam of the radiation, interference filter, mechanism for changing spatial orientation of the filter, radiation intensity meter and control unit. Transmission band of the filter at one position of its spatial orientation partially coincides with at least electron absorption band of component to be measured. Mechanism for changing spatial orientation of interference filter is made for fixing two preset spatial orientations of the filter. Interference filter is made with transmission band which does not either width of electron absorption band of the component to be measured, or width of allowed electron-oscillation absorption band of the component to be measured. Thermostating unit introduced of the interference filter provides temperature stability of its transmission band. EFFECT: improved precision. 4 cl, 4 dwg
