Orbisphere Laboratories Neuchatel Sa

Jean-Paul Pellaux

John M Hale

Nicolas Gisin

Eugen Weber

Ion Bals

Karin Julliard

Francedillaois Gretillat

A method and apparatus for determining the concentration of a substance of interest by gas-coupled photoacoustic spectroscopy (GC-PAS) with an essentially monochromatic beam of radiation in an optical portion of the electromagnetic spectrum; the radiation is selected so as to be absorbed by the substance of interest and the beam is modulated at a sonic frequency which is sufficiently high for generating a primary signal that depends upon the absorption coefficient of the substance of interest as well as upon parameters of operating the method; in order to compensate for these operating parameters, the beam is additionally modulated at a sonic frequency which is sufficiently low for generating a secondary signal which does not depend upon the absorption coefficient of the substance of interest, but, depends only upon parameters of operating the method; a ratio of the first and the second signal is obtained to generate a compensated signal for determining the concentration of the substance of interest.

Spectroscopic method and apparatus

A photoacoustic device for analysis of fluids. The device is made up of (A) a source of a pulsating beam of light, preferably of the chopper type, and (B) an enclosure, preferably an elongated structure having a generally cylindrical, e.g. essentially tubular shape; and containing and holding--in sonic insulation--at least one reference chamber and at least one measuring chamber in an essentially linear or serial arrangement in a common cell within the enclosure, preferably in an essentially coaxial arrangement; the enclosure and the common cell provide a path P for the pulsating beam of light through the reference chamber and through the measuring chamber. For most purposes, it is preferred that the light beam pass first through the reference chamber and subsequently into the measuring chamber. Optionally, a second reference chamber is arranged at the end of the measuring chamber and a second measuring chamber may follow.

Photoacoustic analyzer and method

An analytic device (1) for reflective luminoscopy comprises within an enclosure (11): a light source (12); a pair of spaced light detectors (141, 142); and a refractor body (16); the refractor body comprises a planar base (161), an entry plane (163) near the light source for light emanating therefrom, and an exit plane (165) near the spaced detectors for light that is being sensed by at least one of the detectors; the entry plane and the exit plane enclose an angle of less then 180.degree. and not less than 90.degree., the enclosure further includes a light-collimating means or lens (13) between the light source and the entry plane; a light-collecting means or lens (15) between the light detectors and said exit plane, and at least one light-reflecting surface (171) near the planar base (161); at least one luminoscopic layer (191) normally comprising a luminoscopic indicator and a thin transparent carrier, is arranged between the planar base and the at least one light-reflecting surface; the device includes both a luminoscopic reference as well as a measuring area for a luminoscopic reaction between a luminoscopic layer and a species of analytic interest.

Growing community of inventors

Geneva, Switzerland

Jean-Paul Pellaux