Linda L George

US Patent:

20100294951, Nov 25, 2010

Filed:

May 21, 2010

Appl. No.:

12/800752

Inventors:

Jeremy Parra - Beaverton OR, US
Linda George - Portland OR, US

International Classification:

G01N 21/64
G01J 1/58

US Classification:

2504591, 2504581, 250573, 25022711, 250226

Abstract:

An instrument detects an amount of a component of a sample gas by passing an excitation light through the sample gas at atmospheric pressure to produce fluorescence light from the component. The fluorescence light is discriminated using a sequence of multiple long pass interference filters to filter out the excitation light. The discriminated fluorescence light is then detected to produce a signal representative of the amount of the component in the sample gas. Preferably, the excitation light is continuously passed through the sample gas. In one embodiment, the gas flows through a cell having a parabolic reflector as an interior surface and a source of the excitation light at a focus of the parabolic reflector. In other embodiments, multiple components are detected in parallel using multiple sample cells and a fiber optic multiplexer to sequentially filter and detect the fluorescence light from each of the multiple sample cells.