Varian Australia Pty Ltd

Agilent Technologies, Inc.

Varian Associates, Inc.

Varian, Inc.

Varian Austrailia Pty Ltd

Agilent Technologies Australia Pty Ltd

Michael Ron Hammer

Brian Lawrence Allen

Philip V Wilson

Martin Keith Masters

Peter G Layton

Stewart R Campbell

Thomas Robert Turney

Christopher John Park

Michael Bolles

Dower Cameron Bricker

Robert John Francis

Thomas Erwin Preuss

Mark R Williams

John Pillans

Stewart Ralph Campbell

Peter George Layton

A microwave chamber for plasma generation. The microwave chamber comprises a launch structure at a first end of the microwave chamber to accommodate a microwave source for producing microwave energy and a termination section at a second end of the microwave chamber opposite the first end. The termination section is configured to substantially block propagation of the microwave energy from the second end of the chamber. The microwave chamber further comprises an internal wall structure for guiding the microwave energy received within the microwave chamber at the first end toward the second end and defines a cavity. The internal wall structure comprises an impedance matching section intermediate the first end and the second end, and a capacitive loaded section intermediate the impedance matching section and the second end, wherein the capacitive loaded section comprises at least one ridge extending along a longitudinal axis of the chamber. The microwave chamber defines a first opening extending through a first wall of the capacitive loaded section and a second opening extending through a second wall of the capacitive loaded section. The second wall is opposite the first wall. The first opening and second opening are configured to cooperate with one another to receive a plasma torch in the capacitive loaded section along an axis extending through first opening and second opening and substantially perpendicular to the longitudinal axis of the chamber.

Chambers for microwave plasma generation

A method comprises: aligning a plasma torch within an iris cavity of an iris along a first axis between first and second iris slots having heights less than 70% of the diameter of the torch; and generating an electromagnetic field having field lines along a second axis. The field comprises a component that is substantially transverse to the first direction. An apparatus is also described.

Electromagnetic waveguide and plasma source

An optical absorption spectrometry system includes first and second light sources, a dichroic beam combiner and a wavelength selective module. The first light source emits first light having first wavelengths within a first wavelength range, and the second light source emits second light having second wavelengths within a second wavelength range different from the first wavelength range. The dichroic beam combiner includes a predetermined first reflectance/transmission transition region, the dichroic beam combiner being configured to transmit a first portion of the first light and to reflect a second portion of the second light to provide combined light. The wavelength selective module is configured to disperse the combined light received at an entrance aperture, to select a sample wavelength range of the dispersed light as sample light, and to output the sample light having the selected sample wavelength range from an exit aperture for illuminating a sample.

Optical absorption spectrometry system including dichroic beam combiner and splitter

A calibrated spectroscopy instrument and a method for calibrating a spectroscopy instrument are disclosed. The spectroscopy instrument includes a monochromator having a drive mechanism comprising a pair of spur gears for rotating a diffraction grating of the monochromator for selecting a desired wavelength. The drive mechanism is calibrated to account for eccentricities in the spur gears to provide an accurate conversion between selected angular settings for the drive mechanism and the wavelength of the diffracted light from the monochromator. The drive mechanism comprises a pinion spur gear and a main spur gear which each have an AGMA (American Gear Manufacturers' Association) rating of at least 10, which allows errors due to random tooth to tooth variations to be neglected. A calibration algorithm is derived which is based on the error due to eccentricities in the spur gears following a precise geometric cyclic pattern.

Calibrated spectroscopy instrument and method

A spectroscopy system for spectro-chemical analysis of a sample includes a plasma torch () for generating a microwave induced plasma () as a spectroscopic source. The plasma forming gas is nitrogen which can contain an oxygen impurity. Thus the system includes a nitrogen generator () which is preferably supplied with compressed atmospheric air from a compressor () for oxygen to be removed from the air by adsorption. The invention allows the use of an on-site nitrogen gas generator and thus gives cost savings because the need to obtain supplies of bottled high purity gas is eliminated.

Plasma spectroscopy system with a gas supply

Apparatus () for measuring absolute specular reflectance of a surface of a sample () includes a sample holder (), a light source () for transmitting an incident light beam () onto a surface of the sample () and a detector () for detecting a specularly reflected component of the incident light. The light source (), sample holder () and detector () are mounted and operatively associate () to be relatively moveable to vary the angle of incidence of light () onto sample () and to correspondingly automatically vary the relative position of the detector () such that the angle of reflection equals the angle of incidence. In the absence of the sample () or upon removal of the sample holder (), light () impinges directly onto detector () to directly allow measurement of the absolute intensity of the light beam () as a reference measurement. This avoids the need to use intervening optical components such as mirrors which may degrade over time. It also allows provision of a relatively simplified apparatus.

Measuring specular reflectance of a sample

A plasma source for a spectrometer includes a plasma torch () located within a waveguide or resonant cavity () for both the electric and the magnetic field components of a microwave electromagnetic field to excite a plasma (). This produces a plasma () having a generally elliptical cross section into which sample is relatively easily injected but which still provides good thermal coupling between the plasma and the sample. The invention gives significantly improved limits of detection compared to prior art microwave induced plasma systems. The torch is preferably axially aligned with the direction of the magnetic field component and may be located within a resonant iris () within the waveguide or cavity ().

Microwave plasma source

A method and apparatus for the spectrochemical analysis of a sample in which a solid state array detector ( ) is used to detect radiation ( ) of spectrochemical interest. The invention involves the use of a shutter ( ) adjacent the entrance aperture ( ) of a polychromator ( ) to expose the detector ( ) to the radiation ( ) for varying lengths of time whereby for short duration exposure times charge accumulation in elements (i.e. pixels) of the detector ( ) due to high intensity components of the radiation is limited and for longer exposure times charge accumulation in elements (pixels) of the detector ( ) due to feeble intesity components of radiation ( ) is increased. This ensures that each reading of the detector ( ) includes at least one exposure in which the amount of charge accumulated at each wavelength of interest is neither too little or too great. The problems of feeble radiation components not being accurately measurable and of high intensity radiation components exceeding the charge carrying capacity of elements (pixels) of the detector ( ) are thereby able to be avoided. An attenuator ( ) may be placed between the radiation source ( ) and the detector ( ) to permit longer exposure times to be used for very high intensity radiation.

Method and apparatus for spectrochemical analysis

Spectroscopy apparatus for spectrochemical analysis of a sample having an excitation source ( ) for providing spectral light ( ) of the sample for analysis. The spectral light ( ) is analysed via an optical system ( ) that includes a polychromator ( ) and solid state multielement array detector ( ). The elements (i.e. pixels) of the detector ( ) are serially reel by means ( ) to provide light intensity measurements as a function of wavelength. A problem is that the elements (pixels) of the detector ( ) continue to accumulate change during the serial read-out. This is avoided by providing an optical shutter ( ) for blocking the spectral light ( ) whilst elements (pixels) of the detector ( ) are being serially read. Shutter ( ) has a piezoelectric actuator which is preferably a bimorph mounted as a cantilever. It is preferably located adjacent to the entrance aperture ( ) of the polychromator. Bimorph structures for the actuator and drive and protective circuit arrangements are also disclosed.

Optical shutter for spectroscopy instrument

A plasma source for a spectrometer for spectrochemical analysis of a sample is characterized by use of the magnetic field component of applied microwave energy for exciting a plasma. The source includes a waveguide cavity ( ) fed with TE mode microwave power. A plasma torch ( ) passes through the cavity ( ) and is axially aligned with a magnetic field maximum ( ) of the applied microwave electromagnetic field. Magnetic field concentration structures such as triangular section metal bars ( ) may be provided. In an alternative embodiment a resonant iris may be provided within a waveguide and the plasma torch positioned relative thereto such that the microwave electromagnetic field at the resonant iris excites the plasma.

Plasma source for spectrometry

An ultraviolet/visible/infrared spectrophotometer, with a pulsed light source ( ), has a monochromator with variable slit width to provide variable spectral resolution. The dynamic range at the detectors ( ) is reduced by varying the pulse energy emitted by the light source ( ) in accordance with the wavelength and slit width settings ( ), and/or by varying the slit height in accordance with the slit width. The ligth source ( ) may be a xenon flash lamp.

UV-VIS spectrophotometry

Spectroscopic apparatus for sequentially detecting the presence of a plurality of elements in a sample. The apparatus includes a plurality of lamps (,) each of which is for detecting the presence of a respective at least one predetermined element in a plurality of elements. A beam selector (,) which may be a mirror, is operative to direct a beam of light (,) from any one of lamps (,) to an analysis zone (,). The apparatus includes a monochromator (,), the drive (,) of which is under the control of a controller (,) with a memory device (,) linked thereto. Predetermined settings for the monochromator corresponding to the peak settings for each wavelength of interest can be stored in memory (,) for subsequently driving the monochromator to those settings without the need to undertake a peaking routine for each elemental analysis, thereby saving analyses time. The lamp and beam selector arrangement of the apparatus substantially reduces the time required to change from one lamp to another thereby facilitating sequential spectroscopic multi-element analyses of samples. Apparatus which uses a flame for atomising a sample includes valves (,and,) for controlling the flow of oxidant (,) and fuel (,) gases to a spray chamber (,) and then analysis zone (,), the oxidant (,) being supplied via a nebuliser (,). The valves (,and,) are preferably high speed oscillating valves having an adjustable on to off time ration under the control of a microprocessor (,). The oscillating valves (,and,) allow rapid changes to be made to the oxidant and fuel gas flows, thereby also saving analysis time.

Spectroscopic analysis

Spectrophotometer

A peristaltic pump comprises a rotatable drum 2 having rollers 5 or cams 5' for squashing a flexible tube 9 against a profiled surface 10 of a presser plate 7. Tube 9 is mounted between supports 14 and 15 on presser plate 7 and is automatically movable between an inoperative and operative (pumping) position by pivotal movement of plate 7 about axis 8 produced by an electro mechanical actuator. A flexible membrane 33 is sandwiched between rollers 5 or cams 5' for eliminating shear forces on the tube 9. The construction of the pump and shape of profile 10 are such as to mimimise pulsations in the output flow. Systems for supplying a sample for analysis to spectroscopic apparatus using the peristaltic pump are also described.

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Sassafras, Australia

Michael Ron Hammer