Patent ID: 7251034
Filing Date: 2007-07-31
Classification: G01J,G01N

Abstract:
1. A wavelength modulation spectroscopy method for measuring the concentration (c Meas ) of a gas component of interest in a gas sample, the method comprising the steps of: passing a portion of the light of a light source through a reference gas and thereafter to a reference detector, the reference gas comprising the gas component of interest or another suitable gas component in a known concentration; passing another portion of the light through the gas sample and thereafter to a measuring detector; modulating the wavelength of said light with a frequency (f demodulating the reference detector output (S(ν) providing a mathematical description of the demodulated reference detector output (S(ν) determining said modulation parameters from the demodulated reference detector output (S(ν) generating an output signal representative of the measurement.