U.S. Philips Corporation

North American Philips Corporation

Wilhelmus F Knippenberg

Bernhard N Lersmacher

Gerrit Verspui

Siegfried Hendrik Hagen

Hans J Lydtin

Karlheinz Schelhas

Helmut W Werner

Antonius W Witmer

A cuvette consisting of a basic hollow member of pyrolytic graphite which is treated at least on the outside surface by a local mechanical abrasion is provided for use in atomic absorption spectroscopy. Since the mechanically treated surfaces may form the inner and outer surfaces of the cuvette, it has been found that the cuvette need not be after-coated or sealed with pyrolytic graphite, but may be of a finally finished form following this mechanical abrasion. Accordingly, cuvettes of substantially smaller wall thicknesses, and substantially smaller mass, are formed with the same or even increased rigidity than commercially available graphite cuvettes which may have or not have a pyrolytic graphite coating.

Cuvette for the atomic absorption spectrometry

A cuvette having a thin-walled basic member of pyrolytic graphite is provided with annular graphite components in proximity to its ends. These parts are connected to form a unit which is further coated by an enveloping pyrolytic graphite coating. This cuvette having flanged parts is simpler to electrically contact and is mechanically stable.

Tubular cuvette for atomic absorption spectrometry

A preform made of carbon, and especially electrical graphite (electro-graphite), is given a protective coating of pyrolytic graphite which, in turn, is activated by further coating with a carbon with a very low degree of orientation (soot) or by roughening. The process of activation reduces the effect of the sample to be analysed, while the protective effect of the pyrolytic graphite coating is preserved.

Methods of manufacturing crucible for flameless atomic absorption

An X-ray spectrometer which is arranged inside an evacuatable housing and which comprises a wavelength dependent X-ray detection system and, for irradiating the specimen to be examined, an electron source with an electron deflection system for generating an electron beam and an X-ray source for generating an X-ray beam. The X-ray source consists of an anticathode on which the electron beam can be directed by the electron deflection system in order to generate the X-ray beam.

X-ray spectrometer

A method of making an electric resistor having a negative temperature coefficient of resistance whose resistance body consists of p-type doped pyrolytic polycrystalline cubic silicon carbide.

Method of making an electric resistor having a resistance body

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).

Cuvette for flameless atom absorption spectroscopy

An electric resistor having a negative temperature coefficient of the electrical resistance whose resistance body consists of p-type doped pyrolytic polycrystalline cubic silicon carbide.

Electric resistor based on silicon carbide having a negative temperature

A method of growing silicon carbide whiskers from a gaseous phase by means of a vapor-liquid-solid mechanism on a substrate using iron in a finely divided state as a solvent for the silicon carbide.

Filamentary silicon carbide crystals by VLS growth in molten iron

A method of manufacturing silicon carbide crystals in which a core of silicon dioxide is embedded in a mass of granular silicon carbide, or materials which form silicon carbide on heating this mass being heated to a temperature at which silicon dioxide volatilizes, i.e. above about 1500.degree.C, and the silicon carbide coheres. This leaves a cavity, formerly occupied by the silicon dioxide which is surrounded by silicon carbide. Heating is then continued at a temperature, above about 2500.degree.C, at which silicon carbide crystals are formed on the walls of the cavity.

Growing community of inventors

Eindhoven, Netherlands

Wilhelmus F Knippenberg