Ray M Shepherd

US Patent:

20130239656, Sep 19, 2013

Filed:

Mar 14, 2012

Appl. No.:

13/420233

Inventors:

Aosheng Wang - Eden Prairie MN, US
Ray Dean Shepherd - Tulsa OK, US
Christoph Klawun - Bartlesville OK, US

Assignee:

Siemens Aktiengesellschaft - Muenchen

International Classification:

G01N 30/02

US Classification:

73 234

Abstract:

A gas chromatograph comprising a separation column for separating components of a sample of a gas mixture fed through the separation column by a carrier gas, a thermal conductivity detector including a sensing element arranged downstream from the separation column and configured to detect the separated components in a non-destructive manner and to generate a detector signal in response the detected components, an evaluation unit for evaluating the detector signals to determine concentrations of the detected components, and a further thermal conductivity detector including a further sensing element arranged immediately downstream or upstream from the thermal conductivity detector and configured to detect the separated components and to generate a further detector signal in response to the detected components, where the evaluation unit is configured to compare the detector signal with the further detector signal to recognize and signal a loss of or improper detection by the thermal conductivity detector.