Some content of this application is unavailable at the moment.
If this situation persist, please contact us atFeedback&Contact
1. (EP2955495) METHOD AND SYSTEM FOR CORRECTING INCIDENT LIGHT FLUCTUATIONS IN ABSORPTION SPECTROSCOPY

Office : European Patent Office
Application Number: 15159658 Application Date: 18.03.2015
Publication Number: 2955495 Publication Date: 16.12.2015
Publication Kind : A3
Designated States: AL,AT,BA,BE,BG,CH,CY,CZ,DE,DK,EE,ES,FI,FR,GB,GR,HR,HU,IE,IS,IT,LI,LT,LU,LV,MC,ME,MK,MT,NL,NO,PL,PT,RO,RS,SE,SI,SK,SM,TR
IPC:
G01J 3/433
G01J 3/02
G01J 3/10
G01N 21/27
G01N 21/3504
G01N 21/39
G PHYSICS
01
MEASURING; TESTING
J
MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED, VISIBLE OR ULTRA-VIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
3
Spectrometry; Spectrophotometry; Monochromators; Measuring colours
28
Investigating the spectrum
42
Absorption spectrometry; Double-beam spectrometry; Flicker spectrometry; Reflection spectrometry
433
Modulation spectrometry; Derivative spectrometry
G PHYSICS
01
MEASURING; TESTING
J
MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED, VISIBLE OR ULTRA-VIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
3
Spectrometry; Spectrophotometry; Monochromators; Measuring colours
02
Details
G PHYSICS
01
MEASURING; TESTING
J
MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED, VISIBLE OR ULTRA-VIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
3
Spectrometry; Spectrophotometry; Monochromators; Measuring colours
02
Details
10
Arrangements of light sources specially adapted for spectrometry or colorimetry
G PHYSICS
01
MEASURING; TESTING
N
INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
21
Investigating or analysing materials by the use of optical means, i.e. using infra-red, visible, or ultra-violet light
17
Systems in which incident light is modified in accordance with the properties of the material investigated
25
Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
27
using photo-electric detection
[IPC code unknown for G01N 21/3504]
G PHYSICS
01
MEASURING; TESTING
N
INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
21
Investigating or analysing materials by the use of optical means, i.e. using infra-red, visible, or ultra-violet light
17
Systems in which incident light is modified in accordance with the properties of the material investigated
25
Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
31
Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
39
using tunable lasers
CPC:
G01J 3/027
G01J 3/0297
G01J 3/10
G01J 3/433
G01J 2003/423
G01N 21/274
G01N 21/39
G01N 2021/399
G01N 2201/0612
G01N 2201/121
G01N 2201/1215
Applicants: SERVOMEX GROUP LTD
Inventors: KOVACICH RICHARD P
ALIZADEH BAHRAM
GASKIN IAN C
HOBBY JAMES D
LOPEZ MARTIN
Priority Data: 201405247 24.03.2014 GB
Title: (DE) VERFAHREN UND SYSTEM ZUR KORREKTUR DER SCHWANKUNGEN VON EINFALLENDEM LICHT IN DER ABSORPTIONSSPEKTROSKOPIE
(EN) METHOD AND SYSTEM FOR CORRECTING INCIDENT LIGHT FLUCTUATIONS IN ABSORPTION SPECTROSCOPY
(FR) PROCÉDÉ ET SYSTÈME PERMETTANT DE CORRIGER LES FLUCTUATIONS DE LA LUMIÈRE INCIDENTE EN SPECTROSCOPIE D'ABSORPTION
Abstract: front page image
(EN) A method and system for correcting the effect of intensity fluctuations of the transmitted light in an absorption spectroscopy system used for the detection or measurement of chemical species in a medium, whereby one or more modulation bursts are imposed onto a light beam that passes through the medium. This burst signal may be obtained by modulating the bias current of a tunable diode laser, and the modulation burst signal may be optimally at the second harmonic of the modulation frequency of a wavelength modulated beam to allow usage of the same signal path processing used for the spectroscopic detection of the measurand for a second harmonic detection system. The burst signal can be controlled using a smooth window function to minimise the effects of non-linear perturbations that are inherent in tunable diode laser wavelength modulation spectroscopy systems, of optical interference fringes (etalons) and of the residual light absorption by background chemical species or the measurand at the wavelength coinciding with the modulation burst.
Also published as:
GB2524725