Abstract: Method of optically analysing a sample by directing one or more frequencies of electromagnetic radiation (EMR) through a sample and onto a partially reflective surface that allows EMR directed thereon to be both reflected and transmitted. The reflected EMR is directed back through the sample such that the pathlength through the sample is different for the transmitted EMR and reflected EMR. The transmitted EMR and reflected EMP are both detected by one or more detectors. The optical absorbance of the sample at the one or more wavelengths of EMR is calculated from the difference between the transmitted EMR and reflected EMR.

Abstract: Apparatus for obtaining the gas-phase electromagnetic radiation spectrum of a liquid sample, including an analysis chamber having an inlet and an outlet, wherein the inlet and analysis chamber are such that, in use, liquid sample is drawn into the inlet through capillary action and vaporized therein. The vaporized liquid sample is maintained in the gas-phase within the inlet and the analysis chamber.

Abstract: The present invention relates to a sealable cell for measuring a liquid sample comprising a spectroscopic probe and a removable cap that can accommodate at least the head of the probe, wherein the internal wall of the cap comprises one or more grooves which are disposed so as to allow a liquid sample to enter the head of the probe and air to escape from the head of the probe to enable improved spectra to be obtained.

Abstract: A method for the on-line analysis of a process stream, which process stream is a feedstream to or an exit stream from a steam reformer, which process stream has a temperature of at least 200° C., the components of which process stream are in the vapour phase, which method comprises: (a) taking a slipstream from the process stream; (b) cooling the slipstream to a temperature above its dew point; (c) analysing the cooled slipstream by near infra-red (NIR) spectroscopy to obtain a spectrum characterising NIR-absorbing components of the process stream; and (d) correlating the spectrum obtained to established calibration models from NIR spectroscopy using chemometric techniques to determine the concentration of, and/or to determine the partial pressure of one or more of the NIR-absorbing components of the process stream.

Abstract: Sealable cell for obtaining a reflectance spectrum of a liquid sample using a spectroscopic probe having a removable cap wherein the internal wall of the cap comprises at least one groove that allows air to escape from the head of the probe and a liquid sample held within the cap so that accurate spectra can be obtained.

Abstract: The present invention relates to a sealable cell for measuring a liquid sample comprising a spectroscopic probe and a removable cap that can accommodate at least the head of the probe, wherein the internal wall of the cap comprises one or more grooves which are disposed so as to allow a liquid sample to enter the head of the probe and air to escape from the head of the probe to enable improved spectra to be obtained.

Abstract: A method and apparatus for obtaining the gas-phase electromagnetic radiation spectrum of a liquid sample, which apparatus comprises an analysis chamber having an inlet and an outlet, wherein the inlet and analysis chamber are adapted such that, in use, liquid sample is drawn into the inlet through capillary action and vapourised therein, the vapourised liquid sample remaining in the gas phase within the inlet and the analysis chamber The apparatus may be attached to a process conduit or vessel containing a source of the liquid for analysis, making it suitable for collecting on-line spectra.

Abstract: A process for measuring the NIR spectrum of a sample using a demountable NIR transmission cell of pathlength 2.5 mm or less, said process comprising: (a) measuring the etalon fringes that arise when NIR light passes through the NIR cell in the absence of a liquid sample, (b) using this to calculate the pathlength of the NIR cell (c) introducing the sample to be analyzed in to the NIR cell, and (d) measuring the NIR spectrum of the sample.

Abstract: The present invention relates to a sealable cell for obtaining a reflectance spectrum of a liquid sample using a spectroscopic probe having a removable cap characterised in that the internal wall of the cap comprises at least one groove that allows air to escape from between the head of the probe and a liquid sample held within the cap so that accurate spectra can be obtained.

Abstract: In a process for the production of vinyl acetate by reacting ethylene, acetic acid and an oxygen-containing gas in a reactor to produce a process stream which is removed from the reactor as an outlet stream, the process is improved by maintaining the oxygen concentration of the outlet stream at or near its flammability limit.

Abstract: An iron composition and method for processing the composition that produces a steel alloy having enhanced low temperature toughness, without compromising other desirable mechanical properties, is described. The composition can be used to produce devices, such as saw chain, particularly useful for low temperature applications. In general, the steel composition comprises from about 0.2 weight percent to about 0.4 weight percent nickel, from about 0.2 to about 0.4 weight percent chromium, from about 0.5 weight percent to about 1.0 weight percent carbon, from about 0.3 to about 0.5 weight percent manganese, from about 0.1 to about 0.35 weight percent silicon, and from about 0.08 weight percent to about 0.20 weight percent molybdenum. After heat treating, the steel composition has an average fracture toughness of greater than about 42 ksi in.sup.1/2, and an average modified Charpy energy-to-failure of greater than about 2 ft.lbs at temperatures greater than about -20.degree. F.

Abstract: An iron composition and method for processing the composition that produces a steel alloy having enhanced low temperature toughness, without compromising other desirable mechanical properties, is described. The composition can be used to produce devices, such as saw chain, particularly useful for low temperature applications. In general, the steel composition comprises from about 0.2 weight percent to about 0.4 weight percent nickel, from about 0.2 to about 0.4 weight percent chromium, from about 0.5 weight percent to less than about 1.0 weight percent carbon, from about 0.3 to about 0.5 weight percent manganese, and from about 0.08 weight percent to about 0.20 weight percent molybdenum. After heat treating, the steel composition has an average fracture toughness of greater than about 42 ksi in.sup.1/2, and an average modified Charpy energy-to-failure of greater than about 2 ft.lbs at temperatures greater than about -20.degree. F.