US 12,345,627 B2
Electromagnetic control of absorption and suppression of spectral artifacts
Michael Lawson, Crowborough (GB); Martin Lopez, Crowborough (GB); and Bahram Alizadeh, Crowborough (GB)
Assigned to Servomex Group Limited, Crowborough (GB)
Filed by Servomex Group Limited, Crowborough (GB)
Filed on Sep. 22, 2022, as Appl. No. 17/934,300.
Claims priority of application No. 2113699 (GB), filed on Sep. 24, 2021; and application No. 2211371 (GB), filed on Aug. 4, 2022.
Prior Publication US 2023/0098004 A1, Mar. 30, 2023
Int. Cl. G01N 21/25 (2006.01); G01N 21/31 (2006.01); G01N 21/3504 (2014.01)
CPC G01N 21/255 (2013.01) [G01N 21/3103 (2013.01); G01N 21/3504 (2013.01)] 43 Claims
OG exemplary drawing
 
1. A method for gas detection and/or measurement in an absorption spectroscopy system, comprising:
transmitting electromagnetic radiation from at least one source of electromagnetic radiation, along a transmission path through a gas sample in a measurement volume of an absorption spectroscopy system, towards at least one detector;
flowing a purge gas to at least a first section of the absorption spectroscopy system, which gas-purged first section is isolated from the measurement volume but is within the transmission path of the electromagnetic radiation that is transmitted between the at least one source and at least one detector;
applying at least one of an electric, magnetic or electromagnetic field to at least the gas-purged first section of the absorption spectroscopy system, thereby to suppress or modulate a spectral artefact resulting from absorption by at least one gas species within the purge gas;
using the at least one detector to monitor absorption of electromagnetic radiation by the gas sample in the measurement volume, for at least one absorption wavelength or a wavelength range including one or more absorption wavelengths associated with at least one gas species, by detecting transmitted electromagnetic radiation that is not absorbed; and
analysing an output signal from the at least one detector to determine the presence and/or measure a parameter of at least one gas species within the gas sample.