Bodenseewerk Perkin-elmer Co.

Other

Bodenseewerk Perkin-elmer Gmbh

The Perkin-elmer Corporation

Bodenseeverk Perkin-elmer & Co. Gmbh

Toma Tomoff

Rolf G Tamm

Bernhard W Huber

Wolfgang Chlosta

Winfried K Gonner

Henry Klemm

Heinz W Henninger

Viktor Lochle

Gunther Dencks

Klaus Grossmann

Volker Kempf

Hans G Mohr

Alan Walsh

Gunter Grosser

Klaus Grossman

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.

Dosing device for analyzing apparatus

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.

Driving mechanism for driving an oscillating polarizer

A polarimeter for measuring the rotation of optically active samples comprises a light source which generates a measuring light beam, a polarizer mounted for rotation about the beam axis of the measuring light beam, a driving mechanism for reciprocating rotational movement of the polarizer, a sample vessel, an analyzer behind the sample vessel, a photoelectric detector, and balancing means which are controlled by the signal of the photoelectric detector and by which a position can be achieved in which the polarizer and analyzer are arranged substantially crosswise. The balancing means comprises a steeper motor for rotating the polarizer with an adjusting movement superimposed by the reciprocatingly rotational movement by which adjusting movement a quick coarse balancing of the polarizer plane of the measuring light beam relative to a zero position of the analyzer is achieved. Fine measuring means are provided for the fine measuring of the angle between the polarization plane of the analyzer in its zero position and the polarization plane of the coarsely balanced measuring light beam.

Polarimeter

In an atomic absorption spectrometer, a burner 16 for atomizing a sample is movable between a first and a second position. In the first position, the 'cloud of atoms' is formed in the area of the housing-fixed measuring light beam 14. In the second position, it is formed outside the measuring light beam. The measurement is made in the first position whereby the utilization of the energy of the measuring light beam is optimal. A drift compensation is made in the second position to take care of variations of the lamp intensity and of the detector sensitivity.

Atomic absorption spectrometer

The present application is directed to new and improved apparatus for use in analytical instruments which includes an elongated dosing tube having a tip at one end which is constructed and arranged to move between a sample vessel, a rinsing vessel and an analytical instrument; the other end of the dosing tube being connected in fluid flow communication to a rinsing liquid supply vessel through a sample pump assembly and a rinsing liquid pump assembly; the liquid pump assembly including a pump cylinder having an inlet and an outlet; a pump piston arranged for reciprocal movement in the pump cylinder between a first end position in the discharge direction and an opposite second end position in the intake direction; a first check valve mounted on the inlet of the pump cylinder and a second check valve mounted on the outlet of the pump cylinder; a seal mounted adjacent the outlet which cooperates with the pump piston to sealingly close the outlet when the pump piston is positioned in its first end position in the discharged direction.

Rinsing liquid apparatus for analytical instruments

A gas conducting tube (12) with a flat end (14) cut off at an angle is pivotal above the burner head 10 for lighting the flame of an atomic absorption spectrometer. Gas emerging from the burner is passed through the tube from the first end 14 to a second end 16 where a glow filament 24 is arranged. The diverted gas is lit and flashes back to the burner, whereby the flame thereof is lit. After the flame has been lit, the tube 12 is rotated out of the area of the burner head 10.

DEvice and technique for lighting a flame in an atomic absorption

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.

Method and device for introducing a sample into a graphite tube

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.

Device for atomizing a sample in flameless atomic absorption spectroscopy

An apparatus useful for flameless atomic absorption spectroscopy includes a sample carrier adapted for receiving non-gaseous sample material and means for radiantly heating the sample carrier to effect the uniform thermal decomposition thereof.

Device useful for flameless atomic absorption spectroscopy

A mechanism for automatically supplying sample fluids to a chromatographic column is provided. The mechanism obviates the need for sealed sample containers as well as the need for pressurized gas commonly employed to force sample fluid from the sealed containers.

Sample transport mechanism

An apparatus useful in the flameless atomic absorption spectroscopy analysis of a sample includes an electrically conductive sample carrier adapted to be heated whereby drying and ashing steps can be performed by passing an electric current therethrough. By use of such an apparatus, the temperature at which the ashing process occurs can be controlled.

Apparatus for use in flameless atomic absorption spectroscopy

A chamber useful with an atomic absorption spectrometer includes at least two atomization means installed therein. The means can be serially aligned with the measuring beam or arranged parallel to the axis thereof.

Assembly useful with an atomic spectrometer

A sampling valve useful in liquid chromatography includes a stationary valve member and a valve member movable with respect thereto. The movable valve member includes an axial bore having a cross-section permitting the insertion therethrough of a sample injection needle.

Sampling valve useful in liquid chromatography

Disclosed is apparatus for automatically transporting liquid samples from sample vessels to the burner of a flame atomic absorption spectrometer or a flame photometer. A sample feed tube pivots between a first position with its end disposed in a sample feeding vessel for discharging, in sequence, sample liquid and a flushing liquid into the feeding vessel and a second position with its end in communication with a sample vessel. The sample feeding vessel has an upper opening, a bottom outlet, and a cavity between the outlet and opening having an annular convex interior surface to ensure accurate and repeated insertion of the sample feed tube into the sample feeding vessel when the sample feed tube is moved into its first position and full and complete discharge of the sample liquid into the sample feeding vessel. A control mechanism is provided to prevent discharge of the sample liquid from the sample feed tube unless and until the sample feed tube obtains its first position.

Apparatus for automatically transporting liquid samples to an analyzer

Apparatus for injecting a selected one of a plurality of samples into a graphite tube atomizer of a flameless atomic absorption spectrometer. A sample dilutant or blank solution, a standard solution for calibrating the spectrometer, and each of a plurality of unknown sample solutions are continuously fed into separate overflow vessels mounted in a turntable driven by a servomotor and monitored by a suitable analog-to-digital encoder. Each of the vessels overflow into a common drain channel and the vessels are positioned by a control system so that a small sample from selected vessels that may contain an unknown sample, dilutant, or calibrating standard, is drawn by a pump into an intake tube. A servomechanism then repositions the tube into the graphite tube atomizer and the pump reverses to inject the solution into the atomizer. The control system is programmed to operate in proper sequence: the spectrometer, the intake tube servomotor, and also to position the turntable and operate the intake tube pump as well as a rinse pump that flushes the entire input tube. The dilutant and standard solutions are supplied from large containers positioned on weight monitors that produce alarms when the solutions are nearly exhausted. This alarm system, together with automatic sample feeding and the use of the overflow vessels on the turntable, eliminates the need for continual manual monitoring by a technician.

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Uberlingen, Germany

Toma Tomoff