Abstract: Described herein is a direct-heating column assembly for chromatography, in which a capillary column is enveloped in a tubular mesh formed by a plurality of woven filaments.

Abstract: In elemental analysers with a valve control system of inert gas and oxygen supply, which opens the oxygen supply at preset moments, with regard to the introduction of the sample into the combustion reactor, the oxygen supply is controlled by the detection, over time, of at least one of the parameters, whose variation is determined by flash combustion in the combustion reactor, closing the oxygen supply depending on said state over time. The parameters are brightness, temperature and pressure in the combustion chamber and/or pressure upstream the combustion chamber.

Abstract: A device for measuring the thermal conductivity of a fluid comprising a first detection section with at least one duct in which a gas flows and at least one heat sensitive resistance element placed in that duct, and a second detection section for the detection of an electrical resistance of the heat sensitive resistance elements. The device also comprises a thermoregulator to maintain the first detection section at a constant first temperature and a further thermoregulator to maintain at least part of the second detection section at a constant second temperature independent of the first temperature.

Abstract: Elemental analysis of a sample is carried out in an oxygen atmosphere in a combustion reactor and the volume of oxygen required for analysis is determined by means of the algorithm

Abstract: There is provided a method and apparatus for controlling the carrier gas flow through a gas chromatographic apparatus with capillary column subjected to variations in temperature, through control of feeding pressure achieved following computerized processing of the equation of the carrier flow rate as a function of inlet pressure, column temperature and system structural parameters, including preliminary determination of the system parameters through detection of pressure, temperature and flow rate values in stabilized conditions of carrier passage through apparatus and calculation of a constant representing said parameters on the basis of values detected and in application of the aforesaid equation; storage of aforesaid constant; utilization of constant in the mentioned equation for controlling carrier flow rate through calculation and control of its feeding pressure during utilization of the gas chromatographic apparatus.