Axetris Ag

Andreas Wittmann

Sven Schlesinger

Torsten Platz

Kai Hassler

Urs Boegli

Stefan Manzeneder

Rui Protasio

Michel Studer

Thomas Hessler

Paolo Antonio Losio

Marc-Oliver Zufferey

Pascal Müller

A method for operating an optical measuring system including a wavelength-tunable temperature-stabilized laser light source for measuring the concentration of a target gas in a measured gas, wherein an instantaneous base current Icorresponding to a wavelength &#x3bb;of a target gas absorption line is set so that a wavelength distance &#x394;&#x3bb;defined during calibration between a target gas absorption line for a target gas and a reference gas absorption line for a reference gas is maintained. During operation, a temperature difference in the laser light source, defined in advance during calibration, between the operating points selected at the time of calibration of the reference gas, with a base current I, and the target gas, with a base current I, is maintained by determining the required instantaneous base current Ifor the target gas, as a function of an instantaneous base current Ifor the reference gas.

Method and system for the relative referencing of a target gas in an optical measuring system for laser spectroscopy

A method for operating an optical measuring system for measuring the concentration of a gas component in a measured gas, based on wavelength modulation spectroscopy, wherein a laser light source is operated in a current-modulated manner with a base current Iand a modulation current Iand a laser beam of the wavelength &#x3bb;having a wavelength modulation amplitude &#x394;&#x3bb;is emitted, and the wavelength modulation amplitude &#x394;&#x3bb;of the laser light is kept constant by way of variable setting of the current modulation amplitude &#x394;I. The method provides for keeping a modulated power &#x394;Pat an internal resistor Rof the laser light source constant at the operating point so as to stabilize the wavelength modulation amplitude &#x394;&#x3bb;.

Method for operating an optical measuring system for measuring the concentration of a gas component in a measured gas

An optical measuring system and a method for gas detection, the optical measuring system including a light emitter and at least one light detector arranged in at least one housing, wherein the light emitter emits a modulated main light beam with a mean wave length &#x3bb;with a modulation span &#x394;&#x3bb;. At least one opto-mechanical component, e.g. a housing window including optically effective boundary surfaces, is arranged between the light emitter and the light detector and causes scatter light beams which interfere with the main light beam so that self-mixing occurs and/or etalons are caused. According to the invention the at least one opto-mechanical component is arranged relative to the light emitter and/or the light detector at an optimized distance L which is a function of the wave length &#x3bb;and the modulation span &#x394;&#x3bb; of the main light beam.

Optical measuring system and gas detecting method

This invention relates to a method that makes the measurement of a trace gas concentration invariant or at least less affected to pressure variations in the gas and atmospheric pressure changes. This method neither requires a pressure sensor nor a pressure calibration routine. Furthermore, the method can be applied to other gas species present in the background gas or to the background gas itself that cross-interfere with the target gas of interest. This allows removing any pressure dependency of cross-interference parameters of other gas species and/or the background gas. The new method for accurately measuring a gas concentration is based on optimizing the wavelength modulation amplitude of the laser to minimum pressure dependency.

Method and apparatus for detecting a gas concentration with reduced pressure dependency

Growing community of inventors

Giswil, Switzerland

Andreas Wittmann