Patent ID: 6351309
Filing Date: 2002-02-26
Classification: G01J,G01N

Abstract:
Optical spectroscopy apparatus providing wavelength stabilization and improved precision and accuracy of optical absorbance measurements, the apparatus comprising:light source means for producing a light beam; modulator means for modulating a wavelength of said light source means, said modulator means comprising means for simultaneously modulating said wavelength with a first frequency and a second frequency, said first frequency being different than said second frequency; detector means positioned to receive said light beam for producing output signal means comprising signal means for wavelength stabilization of said light source means and signal means representative of an absorber species quantity; and demodulator means for demodulating said output signal means, said demodulator means comprising first and second demodulator means each performing sequential demodulations, wherein a first demodulating frequency of said first and said second demodulator means is greater than a second demodulating frequency of said first and second demodulator means.