Abstract: A furnace for electrothermal atomization of samples for atomic absorption spectroscopy comprises a tubular furnace body with lateral inlet aperture and sample-holding inner body which has a hollow, generally semicylindrical shape. The inner body is located within the furnace body opposite the inlet aperture and is connected to the furnace body by a single web. In one embodiment the web is provided with axial bores and the inner surface of the sample holder has a plurality of projections forming a portion of a screw thread. In another embodiment, two hollow, generally semicylindrical bodies extend around the furnace body and thereby define a cavity and a slot. The furnace body and two hollow, generally semicylindrical bodies are interconnected by lateral webs. Electrical contacts members are provided on the semicylindrical bodies. The entire furnace is one integral graphite element.
Abstract: Apparatus and methods are disclosed for performing power compensation in a differential scanning calorimeter. The device operates by first subjecting only a reference material, in a single furnace, to a predetermined, variable, temperature program supplied by a program control. The values of the heating power supplied to the reference material are stored in a memory as a function of the temperature measured at the single furnace by a temperature sensor. The sample is then exposed, in the same furnace, to heating powers which are consecutively applied to the furnace, under program control, in accordance with the values stored in memory. The real temperatures of the sample are then measured by the temperature sensor. A supplementary compensating heating power is supplied to the sample, which power varies in accordance with the difference between the stored, programmed temperature and the real temperature in the sense of eliminating this temperature difference.
Abstract: Electrical contact members 20, 22 for supplying transverse electrical current to a tubular furnace member (22) for electrothermal atomization of samples for analysis by atomic absorption spectrophotometry, the tubular furnace member having diametrically opposite, longitudinally-extending contact ribs (84, 86). The contact members (20, 22) form, in operative assembly, a cavity 88 in which tubular furnace member (24) is accommodated and is held between V-shaped channels (44, 76) in contact members (20, 22). Cavity 88 is formed by a recess (36) in one contact member (20) and covered, except for a separating gap, by the other contact member (22). Respective inert protective gas passages (62, 82) terminate at one end in channels 44, 76.
Abstract: A pocket instrument for sampling breath air in situ, includes a microprocessor-controlled directional control valve with needles at an outlet to which needle the sample vessels are attached. The directional control valve is arranged to be connected through another outlet to the atmosphere and to a collecting chamber respectively, which collecting chamber is provided with a feeding device for accommodating and delivering the breath air.
December 2, 1986
Date of Patent:
April 4, 1989
Bodenseewerk Perkin-Elmer & Co., GmbH
Winfried Gonner, Bruno Kolb, Gottfried Machata
Abstract: An atomic spectrometer in combination with an atomizer apparatus for atomizing a test sample into an atomic state for analysis in the atomic spectrometer. The atomizer apparatus includes a heater for heating a sample to free individual atoms of the sample for atomic spectroscopy, a tube member containing a packing of an adsorbent, a reagent adsorbed on the adsorbent which reacts with a metal constituent in a sample to form a metal complex which adsorbs to the adsorbent at a first temperature and is volatile at a second higher temperature for desorption from the adsorbent, and a heater for heating the tube member.
Abstract: In a polychromator, the image plane or the focus line (28) is adapted optimumly to the plane of a detector (26), e.g. to a diode-array. At the same time, an optimum linear wavelength scale is obtained on the detector (26). To this end, an arrangement having a concave grating (14), and an imaging mirror (20) is provided. An optimizing method is described by which both curves can be optimized in converging steps by alternate variation of the distance b between concave grating (14) and mirror (20) and the asymmetry measure G' of the concave grating (14).
Abstract: A burner assembly for an atomic absorption spectrometer having carrier (20) fixed to the burner head (14) and mounting a flame sensor (96) and an ignition device (16) so as to permit a single alignment of the flame sensor (18) and the ignition device (16) relative to the burner head (14) and subsequent movement or adjustment of the burner relative to the housing without changing the mutual positions of the ignition device (16) and the flame sensor (18) and while the flame is burning.
Abstract: A closure and method of assembly for sample vials comprising a cap and a septum with the septum having a plurality of radially extending protrusions for retentive engagement with the cap to retain the septum and annular disk within the cap during positioning of the closure on the sample vial.
Abstract: An apparatus and method for determining the zero line in atomic absorption spectrometers having an atomizer and a burner for atomizing the sample wherein the flow of oxidizing agent supplied to the atomizer is interrupted by means of a switching valve and an additional flow of oxidizing agent is supplied to the burner through a by-pass conduit by-passing the atomizer with the additional flow being equal to the flow of oxidizing agent to the atomizer during operation of the atomizer and the absorption of the measuring light beam defining the zero line.
Abstract: The present invention is directed to a gas control device for controlling the fuel gas and the oxidizing agent supplied to a burner in an atomic absorption spectrometer, which includes a first restrictor and a first pressure regulator for the fuel gas line, and a second restrictor and a second pressure regulator of the oxidizing agent line, the regulators being connected upstream of the restrictors, respectively, and servomotors for reproducibly adjusting the pressure settings of the pressure regulators, respectively.
Abstract: A monochromator comprises a first and a second concave grating. An entrance slit is imaged by the concave grating in the plane as a spectrum. A disc comprises a spiral slot. A section of the slot forms an intermediate slit periodically sweeping transversely across the spectrum. A concave mirror images the fanning point of the concave grating. Thereby the fanned beams are recombined to a single beam. An exit slit is located in an image plane in which an image of the entrance slit is generated. The spectrum can be scanned quickly and cyclically without the gratings having to be rotated. There is also the effect of a double monochromator. Another embodiment comprises two concave mirrors to generate the image.
Abstract: In a grating spectrometer a signal spectrum is measured repeatedly while inserting different filters. The number of the filters and measurements correspond to the number of the occurring grating orders not suppressed. The signal spectra and the transmission characteristics of the filters are stored. A system of equations is achieved, from which a computer calculates the signal partial spectra associated with the individual grating orders. A total spectrum is composed from these signal partial spectra. Separation of the higher grating orders need not be effected optically, for example by cut-off filters.
Abstract: A needle is movable by a servomotor between a position of rest and an operating position in a stationary housing. The needle includes a tip and a first lateral opening close to the tip and a second lateral opening spaced therefrom. A longitudinal passage of the housing through which the needle is guided includes a pair of seals at the lower end and a seal at the upper end. A carrier gas conduit ends in the longitudinal passage axially inwards of the seals. A port communicating with atmosphere ends axially inwards of the upper seal. The arrangement permits a sample extraction from sample vessels closed by a membrane without the sample vessels having to be lifted and pressed against the needle.
Abstract: A sample vessel container in a sampling device for use in gas chromatography includes a rotatable metal block having a circular array of axial bores for accommodating a plurality of sample vessels. A heating jacket operative as an electric heater is non-rotatably connected to a housing, which jacket tightly surrounds in material contact with, and is adapted to heat, the rotatable metal block.
Abstract: In a method for introducing a sample into a graphite tube in flameless atomic absorption spectroscopy a lamella- or crucible-like sample carrier is introduced into the graphite tube from the end face in axial direction. Drying and ashing of the sample is effected outside the graphite tube. The sample carrier may be heated indirectly by radiation or directly by electric current being passed therethrough.
September 24, 1982
Date of Patent:
October 22, 1985
Bodenseewerk Perkin-Elmer & Co., GmbH
Bernhard Huber, Rolf G. A. Tamm, Toma Tomoff, Winfried Gonner
Abstract: A lamella-shaped sample carrier is attached to a tubular carriage and is movable into a graphite tube of a graphite tube cuvette from the end fact below the measuring light beam of an atomic absorption spectrophotometer. The carriage with the sample carrier is movable between an inner position, a dosing position and an outer position. The sample carrier is electrically heated in any position by means of busses. Drying and ashing of the sample take place outside the graphite tube. The graphite tube is then heated to atomizing temperature, while the sample carrier is in its outer position. Subsequently, the sample carrier is advanced into the inner position and heated itself. Thus, rapid atomization of the sample is achieved.
Abstract: In a photometer for measuring atomic fluorescence, a partial light beam is branched off the exciting light beam by means of a mirror having a hole. The partial light beam falls on a scattering disc, from which a reference light beam impinges upon the detector through opposite windows of the measuring cell. A chopper alternately transmits the exciting light beam and the partial light beam. The signal thus obtained at the detector permits compensation of the influence of variations of the light source brightness and of contamination of the windows.
Abstract: Apparatus for use in conducting both static and dynamic thermomechanical analysis includes a load member, one end of which is supported by the sample located in a sample receptacle, eventually in a selected gas atmosphere, in heat equilibrium and the other end of which is loaded statically by a weight or dynamically by the armature of an electromagnet.
Abstract: A plurality of samples subject to the same thermostatting time periods are directed one by one to the inlet section of a gas chromatograph for analysis in accordance with the head space method. To this end, a first heatable sample store adapted to be stepwise advanced is provided, in which thermostatting of the samples is accomplished. A second sample store also adapted to be stepwise advanced is provided, from which sample vessels are transferred one by one into the first sample store.