Instrumentation Laboratory

Allied Corporation

Thermo Jarrell Ash Corporation

Stanley B Smith, Jr

Robert G Schleicher

Allan G Dennison, Jr

Gary M Hieftje

Richard J Belmore

Mario A Sainz

Robert V Jarratt, Jr

George A McLean

Carl Shapiro

Edward C Eldred

Jon N Waterman

Richard C Anderson, Jr

Robert A Fonteyn

A spectroanalytical system includes entrance aperture defining structure for receiving radiation to be analyzed along a first path; collimating structure in the first path for providing collimated radiation along a second path; fixed refraction structure in the second path for spatially separating (refracting) radiation in the second path in a first direction as a function of wavelength; fixed echelle grating structure in the second path for spatially separating the refracted radiation as a function of wavelength in a second direction orthogonal to the first direction and directing the orthogonally dispersed radiation in a beam along a third path that does not pass through the first refraction structure; and two-dimensional array detector structure for detecting the beam of orthogonally refracted radiation.

Spectroanalytical systems

An analysis system includes a sample inlet, a diluent inlet, and a mixing chamber that has an outlet through which a mixture of the sample and diluent is flowed and in which a mechanical mixing member is housed. Positive displacement pumps preferably concurrently flow diluent to the mixing chamber and draw diluted sample to be analyzed from the mixing chamber. Bubble separation apparatus has a first branch connected to a drain and a second branch connected to the analyzer input. In a particular embodiment, the analyzer apparatus includes a nebulizer that controls the flow rate of the bubble-free stream through the second branch, sample excitation apparatus in the form of an induction coupled plasma (ICP) torch for exciting the sample to spectroemissive levels, and means for spectroanalysis of the excited sample at the output of the torch.

Sample analysis apparatus

A chopperless spectroanalytical system of the double beam type in which radiation from a common source is split into reference and analysis beams. The two beams are directed along similar paths such that the analysis beam passes through an analysis region and the reference beam bypasses that analysis region. A monochromator has two spaced aperture regions such that one aperture region provides an entrance aperture for the analysis beam and an exit aperture for a dispersed portion of the reference beam; and the other aperture region provides an entrance aperture for the reference beam and an exit aperture for a dispersed portion of the analysis beam. The beams exiting from the two exit apertures are simultaneously monitored and compared to compensate for errors due to source fluctuations and the like.

Spectroanalysis system

A spectroanalytical method includes the steps of exciting material to spectroemissive levels, dispersing radiation from the excited sample material into a spectrum, positionally locating a reference constituent of the excited material in the spectrum, the reference constituent having a known wavelength offset from an element of interest in the sample material to be analyzed, and then shifting the known wavelength offset by an essentially hysteresis free mechanism and making an analytical measurement at that wavelength offset position of radiation produced by a spectrum from sample material that has been excited to spectroemissive levels.

Method of emission spectroanalysis

An atomic absorption system comprising a radiation source that emits spectral line radiation characteristic of an element to be analyzed, an analysis region open to passage of the beam of radiation from the source and in which a sample of the substance to be analyzed is atomized, source control means for alternately energizing the source at a first intensity level to provide a radiation output that has a narrow spectral line at a wavelength of an element to be detected and at a higher intensity level to provide a radiation output of broader wavelength with intensity suppression at the wavelength of the narrow spectral line, electronic transducing means for developing an electrical signal corresponding to the sensed radiation intensity of the radiation beam that passes through the analysis region, and a log ratio circuit that utilizes integrated electrical signals corresponding to the two source energization intensity levels to provide background corrected concentration information on the element of interest in the analyzed sample.

Spectroanalytical system

A spectroanalytical instrument includes burner structure and a nebulizer for furnishing sample in fog form for flow through a premix chamber to the burner structure. Flow structure extending from a chamber port to a drain port provides a condensate flow path from the chamber to a drain. Trap structure is disposed in series in the flow path between the chamber port and the drain port, and drain line closure apparatus is switched between a first condition in which the drain line is closed and a second condition in which the drain line is opened by a control responsive to liquid in the trap structure such that the drain line is initially closed and is opened automatically in response to accumulation of condensate liquid in the trap structure to enable maintenance of positive pressure in the premix chamber.

Method and apparatus for automatically depositing predetermined reproducible amounts of nebulized samples into a furnace atomizer of an atomic absorption spectrophotometer, the atomizer being provided with an aperture, wherein a plurality of sample containers containing samples to be analyzed are arranged and successively transported on a sample supporting device, with the sample containers being open at their upper ends. The samples are aspirated from the containers via a suitable means and into a nebulizer-mixing chamber device wherein they are nebulized and mixed until such time that the nebulized sample achieves full equilibrium therein. A means is provided for depositing the nebulized and now equilibrated sample from the chamber device through the aperture into the furnace atomizer. The deposition of predetermined and reproducible amounts of nebulized samples is controlled by a means which, in a preferred embodiment, comprises a vacuum source in valved communication with the means for depositing the nebulized sample in a way that aerosol deposition is effected only during the time period when the vacuum source is shut off from the means for depositing the aerosol sample by shutting off the valve. In another preferred embodiment, the means for controlling the amount of aerosol sample being deposited comprises a fluidic switch in communication with the nebulizer-mixing chamber device on the one hand and with the means for depositing the sample on the other. Hence, sample deposition takes place only during the time period when such communication from the chamber device to the deposition means is effected by the fluidic switch.

Automatic sample deposition in flameless analysis

An input control includes first and second keyboard assemblies mounted on a common structural unit, an encoder on the unit, and a plurality of output conductors connected to the encoder for transmitting a binary coded signal when a key is actuated. The first keyboard assembly includes a set of keys that generate the same input control function signals as do the keys in the second keyboard assembly. The structural unit is mounted for rotation between an upright position in which only the first keyboard assembly is operator accessible and an inverted position in which only the second keyboard assembly is operator accessible. A latch is provided for locking the structural unit in either position.

Keyboard type of input control system for an analytical instrument

A highly accurate, rapid scanning monochromator type of spectroanalysis system employs a source of the plasma emission type, a filtering monochromator, and a resolving monochromator. Each monochromator has a dispersing element and the two dispersing elements are arranged to be moved simultaneously but at different rates such that the spectral order of radiation from the source as dispersed by the first dispersing element is different from the spectral order of radiation dispersed by the second dispersing element, together with selectively operable control means for moving the two dispersing elements simultaneously and at the same rate.

Dual monochromator type of spectroanalysis system

An induction plasma system includes a plasma chamber, a high frequency electrical coil that surrounds the chamber, and an oscillator for energizing the coil to establish a plasma maintaining condition in the chamber. The oscillator tank circuit includes the coil, and is tuned so that it is essentially at resonance when a plasma condition is established in the chamber. Ignition means is arranged for initiating a plasma condition, and is constructed such that insertion of the ignition means into the chamber in the absence of a plasma condition shifts the impedance condition in the chamber to essentially the same tuned condition that exists when a plasma condition is established in the plasma chamber, but without need to adjust any component of the tank circuit.

Growing community of inventors

Westford, MA, United States of America

Stanley B Smith, Jr