US 2004/0164238 A1 · PULSED DISCHARGE IONIZATION SOURCE FOR MINIATURE ION MOBILITY SPECTROMETERS

Abstract

A method and apparatus is disclosed for flowing a sample gas and a reactant gas (38, 43) past a corona discharge electrode (26) situated at a first location in an ion drift chamber (24), applying a pulsed voltage waveform comprising a varying pulse component and a dc bias component to the corona discharge electrode (26) to cause a corona which in turn produces ions from the sample gas and the reactant gas, applying a dc bias to the ion drift chamber (24) to cause the ions to drift to a second location (25) in the ion drift chamber (24), detecting the ions at the second location (25) in the drift chamber (24), and timing the period for the ions to drift from the corona discharge electrode to the selected location in the drift chamber.

Claims16

Dependent claims

A method of pulsed discharge for an analytical instrument, comprising:

flowing a sample gas and a reactant gas past a corona discharge electrode of non-radioactive material situated at a first location in an ion drift chamber;
applying a pulsed voltage to the corona discharge electrode to cause a corona which in turn produces ions from the sample gas and the reactant gas;
applying a dc bias to the ion drift chamber to cause the ions to drift to a second location in the ion drift chamber through a medium provided by a drift gas;
detecting the ions at the second location in the drift chamber;
timing a period for the ions to drift from the corona discharge electrode to the second location in the drift chamber;
and
using the timed period to determine an identity of the sample gas.

4 more elements

Dependencies are inferred from the claim text.

Pulsed discharge ionization source for miniature ion mobility spectrometers

Life of this patent

Pulsed discharge ionization source for miniature ion mobility spectrometers

Life of this patent

Abstract

Claims16