Temperature-independent measurements of gas concentration

US6710873B2 · kind B2 · utility

Assignee

• The Board of Trustees of the Leland Stanford Junior University · US

Inventors

• Jian Wang · Rosharon, US
• Ronald Hanson · Cupertino, US

Key dates

• Filing date: Nov 16, 2001
• Grant date: Mar 23, 2004
• Expiry date: Mar 9, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2201/1211
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and apparatus for temperature-independent determination of a concentration of a probe gas in a sample over a selected temperature range between a low temperature TL corresponding to a lowest temperature expected or found in the sample and a high temperature TH corresponding to a highest temperature expected or found in the sample. In accordance with the method, a probe temperature function of the probe gas is determined over the temperature range using a first spectroscopic technique. Then, a second spectroscopic technique is selected, a reference gas is identified and a reference temperature function of the reference gas is determined using the second spectroscopic technique over the temperature range. In particular, the reference gas is identified such that a ratio of the probe temperature function and the reference temperature function is substantially constant over the temperature range. A probe reaction of the probe gas and a reference reaction of the reference gas is then measured by the first and second spectroscopic techniques and the concentration of the probe gas is derived from the probe reaction and reference reaction. The method of the invention can be take ad…