Abstract: There is provided a gas analyzer, including a radiation source, an analytical space through which passes the gas to be analyzed, at least one detector for detecting the intensity of radiation passing through the space, apparatus for facilitating the alternating introduction, into the space, of the gas to be analyzed and a reference gas having a concentration located at least in the upper half of the range of concentrations to be measured by the gas analyzer. The analyzer further includes processing apparatus, having a memory device, to process signals originating in the detector, the memory device adapted to store in a first mode of operation, signals representing instantaneous intensity values of the detected source and, in a second mode of operation, to store signals representing intensity values obtained when the analytical space is filled with the reference gas, a circuit for comparing the instantaneous values with the reference value, and an indicator device for indicating concentration.

Abstract: A source of IR radiation for use with a gas analyzer including a sealed-off enclosure containing at least one molecular, IR-active gas which, upon excitation, is capable of emitting IR-radiation of a known, discrete spectral distribution. The excitation is effected by electrical discharges taking place in a limited portion only of the sealed-off enclosure, the rest of the enclosure serving as reservoir of the gas. The electrodes producing the discharges are disposed outside of the enclosure. A gas analyzer incorporating the source is also described.