Abstract: A torch for producing an inductively coupled or microwave induced plasma for use in spectrochemical analysis. The torch includes a central tube (25) for conveying a flow of a gas carrying sample aerosol to a plasma (17) produced in the torch. The tube (25) has an inlet (31) and an outlet (39) of smaller size than the inlet and is shaped to deliver a substantially laminar flow of the gas at the outlet (39). The tube (25) is tapered along at least a substantial portion of its length such that its cross-section area gradually and smoothly reduces towards its outlet (39) along at least a substantial portion of its length. It has been found that such a tapered tube is resistant to obstruction by salts deposited from samples containing high levels of dissolved solids.

Abstract: A torch for producing an inductively coupled or microwave induced plasma for use in spectrochemical analysis. The torch includes a central tube (25) for conveying a flow of a gas carrying sample aerosol to a plasma (17) produced in the torch. The tube (25) has an inlet (31) and an outlet (39) of smaller size than the inlet and is shaped to deliver a substantially laminar flow of the gas at the outlet (39). The tube (25) is tapered along at least a substantial portion of its length such that its cross-sectional area gradually and smoothly reduces towards its outlet (39) along at least a substantial portion of its length. It has been found that such a tapered tube is resistant to obstruction by salts deposited from samples containg high levels of dissolved solids.

Abstract: A method relating to deposition of a liquid sample mixture in the tubular furnace of a spectrophotometer. The method involves drawing a quantity of each ingredient of the sample mixture into a conduit in a predetermined sequence and also drawing a slug of air into the conduit immediately following the uptake of each ingredient. In the result, a segmented fluid stream is created in which a slug of air separates each two adjacent ingredient segments. The conduit is initially filled with a rinsing fluid and the segmented fluid stream displaces some of that rinsing fluid from the conduit. A slug of air separates the rinsing fluid from the segmented stream. The segmented stream is then discharged in a single operation into the furnace of the spectrophotometer so that mixing of the ingredients occurs at or adjacent the furnace surface.

Abstract: A method and apparatus for mounting the tubular furnace of spectroscopic apparatus to enable a protective atmosphere. The furnace is supported within the housing by annular electrodes engaging opposite ends of the furnace and an annular chamber surrounds the furnace for substantially its full length. A gas feed chamber adjacent each end of the furnace communicates with the respective adjacent end of the furnace through the central opening of the adjacent electrode and also communicates with the adjacent end of the annular chamber through passages provided in the adjacent electrode. Gas is fed simultaneously from each feed chamber into each end of the furnace and annular chamber to flow axially therealong for discharge through an opening in a wall of the housing located intermediate the furnace ends.

Abstract: A method relating to deposition of a liquid sample mixture in the tubular furnace of a spectrophotometer. The method involves drawing a quantity of each ingredient of the sample mixture into a conduit in a predetermined sequence and also drawing a slug of air into the conduit immediately following the uptake of each ingredient. In the result, a segmented fluid stream is created in which a slug of air separates each two adjacent ingredient segments. The conduit is initially filled with a rinsing fluid and the segmented fluid stream displaces some of that rinsing fluid from the conduit. A slug of air separates the rinsing fluid from the segmented stream. The segmented stream is then discharged in a single operation into the furnace of the spectrophotometer so that mixing of the ingredients occurs at or adjacent the furnace surface.