Abstract: Inaccuracies resulting from measuring the internal temperature of absorption spectrophotometer graphite tube furnaces by pyrometric measurements of a spot on the external surface of the graphite tube are overcome by a novel arrangement in which the pyrometer detector measures the interior through the tube end and at an angle that permits a view of the entire interior length without interfering with the spectrophotometer sample beam.

Abstract: Cuvettes of carbonized laminated fabric with a surface layer of pyrolytic graphite are easy to manufacture, have a high mechanical rigidity and no memory effect and enable the operation of analysis apparatuses at normal mains voltage (220 V).

Abstract: A cuvette used in a flameless atomizer is hollow and includes an opening at both ends and a hole in a radial direction substantially at its central portion. The cuvette is made of a conductive material and Joule-heated by currents flowing therethrough. The interior of the cuvette is divided substantially into three sections: a sample mount section at which a sample introduced through the hole of the cuvette is disposed; a light beam path section through which light incident from the opening at one end of the cuvette passes and goes out of the opening at the other end; and an absorption cell section at which the light beam path section intersects with atomic vapors generated from the sample disposed at the sample mount section. The electric resistance of the cuvette is made smaller at the sample mount section than at a portion near the absorption cell section. This allows the higher temperature of the portions near the absorption cell section than that of the sample mount section.

Abstract: A novel approach to sample deposition in furnace atomization is disclosed which obviates the need for skilled application of microvolumes by syringe. By means of the apparatus and method disclosed, the analyte in aerosol form is deposited under controlled conditions on the internal surface areas of graphite furnaces. Precision approaching that of flame atomization systems is achieved and at the same time, concentrational sensitivity may be increased simply by extending the deposition time. The amount of analyte deposited in the furnace is restricted only by the sample volume available and the matrix concentration. A single standard can be used to construct a calibration curve by simply varying the aerosol deposition time.

Abstract: Apparatus for directly controlling the power delivered to an electrically heated furnace atomizer for use in atomic spectroscopy and thus for controlling the temperature of the furnace by utilizing dimensional changes produced in the furnace due to thermal expansion and contraction to produce electrical signals that are used by means of a feedback control to control the electrical input to the furnace.

Abstract: The graphite sample tube used in flameless atomic spectroscopy is mounted in coaxial bores of two separated heating electrodes, each supported by a cooling jacket for carrying off the excess heat produced by the sample tube. Instead of being sealed with sealing rings, the cooling jackets contain seamless tubing that is tightly pressed in the grooves and carries a flow of suitable coolant. The tubing eliminates fluid eddies and thermal stresses which inevitably leads to coolant leaks. An additional feature is that one of the two cooling jacket housings is pivotally movable by a pneumatic actuator for easy removal of the graphite sample tubes and the inspection of the bores of the electrodes.

Abstract: A graphite tube atomizer for flameless atomic absorption spectroscopy includes a graphite tube disposed to permit passage of a measuring beam therethrough. The graphite tube is engaged at opposite ends by annular contact pieces which are coupled to a source of electrical current. The contact pieces are supported in housing portions which serve to surround the graphite tube and provide a chamber into which cooling gasses can be admitted. The cooling gasses also serve to reduce deterioration of the graphite tube. The housing portions are selectively movable either toward or away from each under the power of a drive mechanism. The housings may be urged by the drive mechanism toward each other so the contacts mounted thereon are in selectable pressure engaging contact opposite ends of the graphite tube.

Abstract: In an element analyzer exploiting a magneto-optic effect, when a concentration of the element in a sample material to be detected is high, two peaks are produced in the wave form of the signal obtained during the measurement. The present invention provides a discriminating technique to indicate whether two peaks appear in the wave form of the signal, with the object of reducing the error produced in the element analysis exploiting a magneto-optic effect.

Abstract: This application discloses a spectrophotometer employing a magneto-optic effect which enables quantitative analysis of a sample to be measured by a double beam method. In performing the double beam method for analyzing the sample, a magnetic field is applied to the sample along with linearly polarized light from a light source, the forward scattered light scattered by the sample atoms and the incident linearly polarized light from the sample are converted into two cross-polarized beams of light using an analyzer, and these two beams of cross-polarized light are spectrally analyzed by a single dispersive element. The spectrophotometer of the invention provides an arrangement such that the plane defined by the above-mentioned two beams of light is perpendicular to the plane of dispersion of the dispersive element, and the two beams of light so dispersed are independently detected by separate detectors.

Abstract: A magneto-optic spectrophotometer for detection or identification of atoms or molecules contained in the sample by utilizing phenomena of birefringence or rotation of polarization caused by the atoms or the molecules in a magnetic field is constructed as follows. Linearly polarized lights are incident on a space where atoms or molecules to be detected exist in a magnetic field. The lights having passed through said space are separated into two beams of lights of polarization components perpendicular and parallel to the polarization of the incident lights. The perpendicular components are used as the signal lights, and the parallel components the reference lights. The signal lights and the reference lights are spectrally analyzed by a wavelength selector in which a signal light and a reference light of a wavelength to be selected are incident on an identical dispersive element. The signal lights and the reference lights are detected by respective detectors.

Abstract: The desired element in a specimen to be analyzed by atomic absorption spectroscopy is deposited in the spectroscope measuring tube in a concentrated form by first distilling away all components of the specimen that are more volatile than the element, then increasing the heat to distill off the desired element which is condensed on the cooler walls of the measuring tube while all components less volatile than the element will remain in the adjacent heated specimen crucible.

Abstract: Chemical analysis apparatus such as a spectrophotometer including an atomizer for receiving a sample to be analyzed and being heated by resistance heating. Control means being provided to vary the voltage across the atomizer, and consequently its temperature, and a feedback circuit is connected between the atomizer and the control means and includes components which are operable to generate an electrical analogue which at least approximates the heating response characteristics of the atomizer. The feedback circuit functions as a negative feedback loop so as to modify the power input to the atomizer by application of the aforementioned electrical analogue, and in that way substantially compensates for the heating response characteristics of the atomizer such that the temperature time profile of the atomizer follows a predictable path.

Abstract: Disclosed is an apparatus and method for using same for atomic absorption determination of volatile, thermally decomposable compounds. The test sample is converted to a gaseous sample in a reaction vessel with an inert gas atmosphere. The gaseous sample in the inert gas is then introduced into a heatable measuring cell arranged in the ray path of an atomic absorption spectrometer. To further assist decomposition, the inert gas is heated prior to entering the measuring cell.

Abstract: The combustion of hydrogen at the open ends of an atomic absorption spectrometer heated atomizing tube that is being supplied with substances or reagents containing volatile hydrides is eliminated by tube extensions of low heat conductive material that lower the temperature of the gas below its flash point.

Abstract: Chemical analysis apparatus such as a spectrophotometer, having a carbon rod or other non-flame atomizer which is adapted to be heated by electrical resistance heating. The atomizer is included in a heater circuit, and a particular relationship exists between the electrical resistance of the atomizer and the electrical resistance of the remainder of that circuit. That relationship is such that variations in the atomizer resistance as may occur over a period of use, do not substantially affect power dissipation in the atomizer during heating. Ideally, the two resistance values are equal, but variations from the ideal are satisfactory in practice. A feed-back circuit is arranged to maintain a substantially constant voltage across the heater circuit, and that is achieved by comparing the applied voltage with a reference voltage and modifying the applied voltage as necessary to maintain a predetermined relationship between the two.