Abstract: A process and apparatus for the determination of the organically bound carbon content in water containing organic substances and a high concentration of salt. This is accomplished by exposing a water sample that is to be analyzed to ultraviolet radiation until the entire carbon content contained in the organic substances has been oxidized photochemically into CO.sub.2. The amount of CO.sub.2 thus developed is analyzed quantitatively as a measure of the content of organic substances and, thus, of the organically bound carbon contained in the water. Every water sample to be analyzed is inserted into an aqueous reaction medium which is free of carbon and which is essentially free of salt.

Abstract: A nondispersive gas analysis device with minimal cross-sensitivity to interfering gases includes cuvettes for a sample gas and a reference gas which are irradiated by modulated infrared energy. Radiation which has passed through the cuvettes passes unidirectionally and successively through receiving chambers which are dimensioned to be geometrically and optically alike. The chambers are coupled through conduits to a pressure responsive differential signal generator unit. Loss of radiation intensity due to the window between two sets of receiving chambers is compensated for by using suitable optical coatings on the receiving chamber windows or by forming the walls of the upper set of chambers from a material having a thermal conductivity differing from that of the material used in the lower set. An absorption chamber positioned after the receiving chambers has an IR absorbing disc with a plurality of concentric grooves formed to define a sawtooth pattern.

Abstract: A body has two bores defining two cuvette chambers, one for holding a comparison gas and the other for holding a gas to be analyzed by comparison with the first. An infrared (IR) source at one end of the body provides in-phase radiation into the two cuvettes. At the other end is a window, a selective filter, a reception chamber for each cuvette, and an absorption chamber. The reception chambers are coupled to a device for producing a signal representing the difference in radiation reaching the reception chambers. The reception and absorption chambers are separated by a low reflectance window and the absorption chamber contains an IR absorbing body of glass, polymethacrylate or the like with concentric grooves.