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US 5,317,271 AGranted
High voltage spark excitation and ionization detector system with adjustable sample input for sensitivity control
AssigneeValco Instruments Company, L.P.
InventorsWayne E. Wentworth, Stanley D. Stearns
Life of this patent
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Abstract
A sample is loaded along with a carrier gas into a column. The column discharge is introduced into a chamber downstream of spaced electrodes which create a pulsed DC spark. The spark produces a spectral emission and a metastable carrier gas dispersion that then reacts with molecules of the sample to bring the sample to an excited state. The excess energy surrendered by the sample is characteristic of the species and can be measured by detector electrodes in the chamber.
Claims25
A charged particle detector comprising:
- (a) a closed chamber having a carrier gas flow inlet at a first end and spaced outlet at a second end to enable gas flow therethrough;
- (b) spaced electrodes forming a spark responsive to DC current flow sufficient to enable an electrical spark to be formed between said electrodes locating the spark thereacross, said electrodes being positioned to form a spark in carrier gas flow into said chamber and create charged particles;
- (c) a spaced detector electrode in said chamber for collection of charged particles downstream of the spark across the gap wherein the charged particles move toward said detector electrode to enable a current to be formed indicative of charged particle concentration in said chamber;
- and
- (d) an inlet into said chamber for controllably introducing a sample gas flow from a GC source downstream from said spark forming electrodes so that said sample gas flow and said carrier gas flow provide charged particles for said detector electrode.
2 more elements
A method of analyzing a sample compound comprising the steps of:
- (a) flowing a carrier gas through a chamber;
- (b) exposing the carrier gas to a repetitive DC current spark;
- (c) forming energized particles as a result of the spark through the gas;
- (d) introducing a gaseous sample into the chamber;
- (e) mixing the energized particles with the gaseous sample, and dispersing the energized particles into the gaseous sample;
- (f) measuring a characteristic of the energy state of the gaseous sample;
- and
- (g) wherein the measurement step occurs after mixing the gaseous sample with energized particles of the carrier gas.
5 more elements
A gas detector for identification and quantification of sample compounds, comprising:
- (a) an elongate chamber having a chamber inlet at one end and an outlet at the other end, and a gas flow path between said inlet and outlet ends;
- (b) means for flowing carrier gas through said chamber between said inlet and outlet ends;
- (c) two electrodes spaced apart and located at said inlet to produce short repeated high voltage DC current sparks across said gas flow path and wherein spark duration minimizes electrode erosion while forming energized particles in the chamber;
- and
- (d) means for introducing sample gas into said chamber;
- and
- (e) means responsive to the energy states of the interacted sample gas and charged particles of the carrier gas from to enable detection in said chamber.
4 more elements
A gas detector for identification and quantitation of sample compounds, comprising:
- (a) an elongated chamber having a chamber inlet at one end and an outlet at the other end, and a gas flow path between said inlet and outlet ends;
- (b) means for flowing carrier gas through said chamber;
- (c) moveable means for introducing sample gas into said chamber at a varied location;
- (d) two electrodes spaced apart and located to produce short repeated high voltage DC current sparks within said chamber and across said carrier gas flow path and wherein spark duration minimizes electrode erosion;
- and
- (e) wherein ions are produced by the spark or by excited metastable species of the carrier gas.
3 more elements
Detecting apparatus comprising:
- (a) an elongate chamber having an inlet at one end and an outlet at its other end, and a carrier gas flow path between said inlet and outlet;
- (b) spaced discharge electrodes disposed within said chamber to form an electrical discharge gap between such electrodes in said gas flow path of said chamber;
- (c) means for flowing a sample gas into said chamber without flowing through said electrodes;
- (d) means for repetitively applying electrical discharges across said discharge gap of said spaced electrodes in the path of a carrier gas thereby changing the atomic state of said carrier gas;
- and
- (e) means for measuring a characteristic of the charged atomic state of said sample gas.
3 more elements
A method of measuring a characteristic of a gas sample comprising the steps of:
- (a) providing an elongate chamber having an inlet at one end and an outlet at its other end and a gas flow path between said inlet and outlet, and having spaced discharge electrodes disposed within said chamber to form an electrical discharge gap between such electrodes in said gas flow path of said chamber;
- (b) flowing a carrier gas first through said electrical discharge and along said gas flow path of said chamber;
- (c) repetitively applying electrical discharges across said discharge gap in the path of said carrier gas thereby changing the energy state of said carrier gas;
- (d) introducing a sample gas into the chamber downstream of said spark forming electrodes;
- and
- (e) measuring a characteristic of the energy state of said sample gas.
3 more elements
An apparatus for measuring the optical emissions unique to a sample comprising:
- (a) chamber means having an optically transparent window at a first end of said chamber means for enabling light to pass through said window;
- (b) inlet means directing a flow of an inert gas into said chamber means wherein the flow sweeps over a region adjacent to said window;
- (c) an outlet from said chamber at a second end of said chamber means;
- (d) spark forming means in said chamber located so that a spark formed thereby forms light emitted by the spark, and the light is directed toward said window;
- and
- (e) means for introducing a gas sample into said chamber means to enable said sample to be introduced into the spark and thereby form light characteristic of said sample so that light passing through said window characteristically represents the sample, wherein said means for introducing a gas sample is downstream of said inert gas inlet means.
3 more elements
Dependencies are inferred from the claim text.