Abstract: The flow-injection system includes a microwave oven having a flow-through reactor having a flow-through conduit located in windings around a conduit carrier for absorbing microwaves. The windings extend through the radiation cavity of the microwave oven only with a part of their length and transversely to the radiation direction. The microwave oven includes programmable adjusting means for the heating power and the heating period. Thus, in connection with a reduction flow-through reactor and an atomic absorption spectrometer, a determination of hydride formers and mercury in a material sample is possible, independently of the valence state.

Abstract: A graphite tube for electrothermal vaporization of a sample to be investigated is held between annular contacts through which a flow can be passed lengthwise through the graphite tube. The contacts surround the graphite tube in a shell-like manner; a protective gas flow can thus be passed into a cavity which is formed between the graphite tube and the contacts. The contacts are retained in cooling blocks. The sample is introduced into the graphite tube, vaporized, and carried into the plasma by means of a carrier gas flow which is passed through the longitudinal bore of the graphite tube. The graphite tube contains a radial sample infeed opening which can be closed by a controllable closure member applied to the graphite tube.

Abstract: A tubular furnace having an inner body connecting by an integral radially extending web. The web is positioned on the side of the tubular furnace so that a sample placed in the inner body and resting in the bottom thereof will not be heated by the web. Other embodiments illustrate the web positioned at different axial locations.

Abstract: In a dosing device for analyzing apparatus, particulary for liquid chromatography, with a dosing loop, a change-over valve and a dosing needle (20) which can be introduced into a sample inlet (56) of the change-over valve (24), through which dosing needle (20) sample liquid can be dosed by means of a sample pump (66) into the sample inlet (56) and the dosing loop (22), the dosing needle (20) has a conical sealing surface (138) at its front end. The sample inlet (56) has a sample inlet passage (128) which forms a conical annular shoulder (136). The dosing needle (20) with its conical sealing surface (138) engages this annular shoulder (136) with a defined pre-stress.

Abstract: An atomic absorption spectrometer contains a line-emitting first light source (16), an official system (20, 22, 28, 30, 34) for generating a measuring light beam (18) which passes through a test sample space (12) and impinges on a photoelectric detector (38). An atomization device (14) for atomizing a test sample is so arranged in the test sample space that the constituents of the test sample are present in atomic form in an atomization region traversed by the measuring light beam (18). A light beam (72) is emitted continuously by a second light source (70). A beam splitter (74) reflects the light beam from the second light source (70) as a reference beam into the optical path of the measuring light beam (18). The two light sources (16, 70) can be switched on alternately by switching means. The beam splitter (74) can be removed optionally from the optical path.

Abstract: A double monochromator comprises an inlet slit 20, which is imaged in the plane of an intermediate slit 34 through a first grating monochromator 36. The intermediate slit 34 is imaged in the plane of the outlet slit 34 through a second grating monochromator 58 identical with the first grating monochromator 36. Deflecting mirrors 64 and 66 can be moved into the path of rays to enable such a double monochromator to be optionally used as a single monochromator with increased light flux. An additional slit is arranged between the deflecting mirrors 64 and 66. The arrangement is such so that essentially identical beam geometries result at the outlet in both of the operation modes.

Abstract: Method for analysis of samples by means of atomic absorption spectroscopy with electrothermal atomization of sample consists of the method steps: (a) introducing a liquid sample into a furnace, (b) heating the furnace up to a drying temperature for drying the sample, (c) subsequently heating the sample up to an atomizing temperature, in which a cloud of atoms develops in the furnace, in which cloud of atoms the components of the sample are present in atomic state, and (d) measurement of the atomic absorption of a measuring light beam with resonance spectral lines of an element looked for in the sample guided through the cloud of atoms. In this method (e), the vapors formed in the furnace during the heating of the furance up to the drying temperature are sucked off by a vacuum. Also, a device for carrying out this method is described.

Abstract: A photomultiplier (10) with an elongated rectangular, cathode (20) tilted with respect to the inlet opening (14) is alternately illuminated by a measuring light beam (36) and a reference light beam (40). The measuring light beam (36) and the reference light beam (40) extend in a plane parallel to the longitudinal sides of the cathode (20) and impinge upon the cothode (20), such that they illuminate the same areas of the cathode (20).

Abstract: The manufacturing of a furnace for electro-thermal atomization of samples for spectroscopical purposes having a cavity for the accommodation of sample is simplified and improved. To this end, the furnace consists of two halves which are joined along a separating plane intersecting the cavity. The furnace is made of graphite and provided with a layer of pyrolytic graphite. A platform for the accommodation of the sample is integral with one of the halves.

Abstract: In a device for analyzing samples for mercury and/or hydride-forming elements by means of atomic absorption spectroscopy, a first arrangement for determining the mercury according to the amalgam method comprising passage throttling means in the form of a washing bottle and a tube connected downstream to a reaction vessel, the other end of which tube is connected to the measuring cell. The tube contains a gold net adapted to be heated and recooled according to the amalgam method. The second arrangement by which hydrides of the sample are directly connected to the measuring cell employs a conduit which leads directly to the measuring cell, bypassing the gold net by branching off from between the reaction vessel and washing bottle. The tube is connectable to a carrier gas source between the washing bottle and position of the gold net in the tube through a first shut-off valve. A second shut-off valve is arranged in the conduit directly leading to the measuring cell.

Abstract: An atomic absorption spectrometer with electrothermal atomization of the sample and background compensation by use of Zeeman effect comprises a furnace (130) for the electrothermal atomization of the sample which furnace is heated transverse to the direction of propagation of the measuring light beam (18) of the atomic absorption spectrometer and a switchable solenoid (44) for generating a magnetic field at the location of the sample which magnetic field extends parallel to the direction of propagation of the measuring light beam (18) such that the longitudinal Zeeman effect is obtained with switching on the solenoid (44). The solenoid (44) has pole pieces (46,48) with aligned apertures (50,52) for the passage of the measuring light beam (18). A contact carrier (96) is arranged on the pole pieces (48,50) in which contact carrier contacts (128,176) are supported in order to hold the transversely heated furnace (130), the axes of said contacts being perpendicular to the axis of the measuring light beam (18).

Abstract: A method of and a device for multi-element measurement of elements in a sample with correction for background emission. The method starts with atomizing a sample and then exciting the transformed atoms to emit light containing characteristic spectral lines for each element, followed by generating a spectrum of spectral lines characteristic of the elements, followed by measuring the intensity of selected spectral lines falling within a predetermined measuring range without changing their intensity. The next steps are sensing the background emission adjacent the selected spectral lines simultaneously with measuring the intensity of selected spectral lines and determining the concentration of each element from the measured intensity of the corresponding spectral line and sensed background emission.

Abstract: A method for determining concentration by means of atomic absorption spectroscopy, whereby the sample is supplied to a continuously operating atomizing device of an atomic absorption spectrometer by flow injection technique and generates a transient output signal of the atomic absorption spectrometer, comprises the method steps of supplying a calibration sample with a known concentration of the looked-for element to an atomic absorption spectrometer by flow injection technique, the concentration of the element looked-for in this sample being in a range of minimum standard deviation; storing the obtained transient calibration signal; supplying a sample which is to be analyzed and has an unknown concentration of the looked-for element to the atomic absorption spectrometer by flow injection technique and measuring a transient sample signal; forming signal ratios of the sample signal and the calibration signal at mutually corresponding predetermined moments of time; and determining the concentration of the looked

Abstract: A system for introducing a sample substance into a spectroscopical analytical instrument which includes a first pump which, when on, pumps a sample liquid and a buffer liquid, and a second pump which, when on, pumps an eluting liquid and rinsing liquid. The system includes an ion exchanger column for retaining the elements of the sample to be determined and which can be eluted by the eluting liquid. A dosing capillary serves to introduce the sample into the furnace of an atomic absorption spectrometer. A valve has a first position wherein the first end of the ion exchanger column communicates with the first pump and the second end communicates with a waste outlet port, and the dosing capillary communicates with a source of displacing fluid; and a second position wherein the second end of the ion exchanger column communicates with the second pump and the first end communicates with the dosing capillary.

Abstract: In an atomic absorption spectrophotometer for multielement analysis, the light from a plurality of light sources each of which emits the resonance lines of one associated looked-for element is superimposed into a single light beam by means of interconnected light guides. The light is directed onto a polychromator 64 via an optical coupler.

Abstract: A device for electrothermal atomization of samples for spectroscopic purposes with a furnace body made of graphite, designed such that electrical current can be passed through, and a pot-shaped sample receptacle which is separated from the furnace body and projects into a lateral aperture of the furnace body comprises a driving device by which the sample receptacle is movable into and out of thermal contact with the furnace body. The driving device together with the heating current of the furnace body is controlled by a controlling device such that the sample receptacle engages the furnace body during a drying and decomposing step and thereafter, is raised from the furnace body by the driving device. Thereafter, with raised sample receptacle, the furnace body is heated to atomization temperature until a temperature stabilization is achieved and, finally, the sample receptacle is again moved into contact with the furnace body.

Abstract: The control apparatus controls the lowering motion of an aspirator tube into a sample vessel in an automatic sample dispenser in a manner such that the smallest possible portion of an external surface of the aspirator tube is wetted by a liquid present in the sample vessel. A servo drive lowers the aspirator tube into the sample vessel. A sensor arrangement containing a single light guide, a light transmitter and a photoelectric receiver is associated with the aspirator tube and responds to light reflections at the liquid surface upon immersion of the lower aspirator tube end into the liquid. The light guide guides the propagating light beam and a returning reflected light beam. An electronic control controls the advancement of the aspirator tube via the servo drive into a position in which a predetermined short length in the region of the lower aspirator tube end dips into the liquid.

Abstract: The volatile sample is entrained by a carrier gas flow leading to a measuring arrangement of an atomic spectrometer through a carrier gas conduit. A tube section containing a gas permeable, inert filling is placed in the carrier gas conduit. A cooling jacket is associated with this tube section. The volatile sample is frozen out and/or adsorbed at the filling. Subsequently, the filling is heated by at least one infrared radiator through the cooling jacket whereby the deposited volatile sample is vaporized and supplied to the measuring arrangement in concentrated manner.

Abstract: An improved electro-optical ion detector comprising a channel electron multiplier assembly located at the angled focal plane of the magnetic sector of a scanning mass spectrometer with a twisted fiberoptic window with a means for precisely optically coupling the assembly to the twisted fiberoptic window. Means are provided for precisely spacing the entrance end of said twisted fiberoptic window in the form of a foil of a selected thickness. Also disclosed is a method for making an improved electro-optical ion detector.

Abstract: In a driving mechanism for driving an oscillating polarizer in a polarimeter, the polarizer is driven by a stepper motor which is controlled by a computer to make a reciprocating movement. A reference position sensor is connected to the oscillating polarizer, to provide a reference signal when the oscillating polarizer is in a determined position. A zero position of the reference position sensor is obtained by spacing the reference position sensor a predetermined number of steps of the stepper motor.