Method of calibrating a wavelength-modulation spectroscopy apparatus using a first, second, and third gas to determine temperature values to calculate concentrations of an analyte in a gas

US8217376B2 · kind B2 · utility

Assignee

• GE Infrastructure Sensing, LLC · US

Inventors

• Xiaoyong Liu · San Jose, US
• Yufeng Huang · Chesapeake, US
• John McKinley Poole · Maynard, US
• Gene Smith Berkowitz · Sudbury, US
• Anthony Kowal · Berlin, US
• Shawn D. Wehe · Niskayuna, US
• Hejie Li · Schenectady, US

Key dates

• Filing date: Apr 11, 2011
• Grant date: Jul 10, 2012
• Expiry date: Apr 11, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G01J3/4338
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Several methods of calibrating a wavelength-modulation spectroscopy apparatus configured to measure a concentration of an analyte in a sample gas are disclosed. Each of the methods allows for calibration and recalibration using a relatively safe gas regardless of whether the sample gas for which the concentration of the analyte can be determined is a hazardous gas. In one embodiment of the invention, calibration that is sample-gas specific is accomplished by determining a first slope coefficient and calibration function for the sample gas, after which a scaling factor can be determined based on the first slope coefficient and a second slope coefficient for the same or a different sample gas and used in a subsequent calibration (or recalibration) to scale the calibration function. In other embodiments of the invention, calibration that is not sample-gas specific is accomplished to allow for the determination of the analyte concentration in variable gas compositions and constant gas compositions.