Abstract: A sample introduction valve for spectrometers for selectively directing sample flow from two or more sources in which a slideably mounted shuttle provides in one position a pass through for one source and a by-pass for the other source and in a second position the opposite result.
Type:
Grant
Filed:
June 10, 1991
Date of Patent:
May 24, 1994
Assignee:
Leeman Labs Inc.
Inventors:
David A. March, Peter G. Brown, David A. Hotham
Abstract: A nebulizer for producing a quantity of fine liquid droplets consisting of a screen over which the liquid to be nebulized is flowed and a nozzle for directing a stream of gas at the screen. The force of the gas against the screen creates the droplets by shearing the liquid from the spaces in the mesh. A second screen in front of the first may be used to increase the uniformity of the output.
Abstract: A sample transport and manipulation system and method for exciting a quantitatively uniform sample for spectrometric analysis over an extended period of time is disclosed. A uniform sample transport medium such as a filament is transported at a uniform rate through an excitation situs which is coincident with the optical input situs of the spectrometer. Means for uniformly depositing a liquid sample over the medium are included to complete the establishment of a system in which the spectrometer is presented with a quantitatively uniform excited sample on a continuous basis.
Abstract: A sample manipulation system for spectrometers is disclosed in which an electrically conductive filament is arranged to receive and hold a liquid containing sample. Various levels of electrical power are employed to heat the filament for such purposes as increasing the affinity of the filament for the liquid, evaporating the liquid after deposition, ashing the remaining sample, and exciting the sample. Separate contact points are provided for each power level as well as means to successively connect at least one end of the filament to each contact point.
Abstract: A scannable detector system for echelle grating spectrometers is disclosed in which a photodetector is positioned behind an aperture plate having a plurality of apertures corresponding to focal positions of the spectral array eminating from the grating. The detector is arranged to scan from aperture to aperture to measure the presence of individual wavelengths in the array. Additionally, the detector may be removed from the field of the plate to permit the substitution of a non-scannable array of detectors and an associated masking aperture plate to simultaneously measure the presence of a plurality of wavelengths in the spectral array.
Abstract: A stabilized cathode assembly for an arc light source is disclosed wherein an unattached end of a length of electrically conducting braid serving as a cathode is held in close proximity to the anode of the source to establish an arc path between the braid end and the anode. Support means are disclosed which function to advance and withdraw the braid to initiate the arc. Application of the assembly in a spectrometer sample excitation device is further disclosed.
Abstract: A sample excitation situs or light source enhancement apparatus for an optical spectrometer comprising a mirror arranged to reflect an image of the excitation situs in close proximity to the actual excitation situs is disclosed.