Improving the accuracy and sensitivity of 13C online detection in expiratory air using the TDLAS method in the spectral range of 4860-4880 cm-1

Implementing Kalman and Savitzky-Golay adaptive filters to process experimental signals and improve the sensitivity and accuracy of the measurements of the content of (CO2)-C-13 in human expiratory air with the tunable diode laser absorption spectroscopy method while using a laser diode as a tunable source in the range of 4860-4880 cm(-1) near a wavelength of 2 mu m has been reported. It is established that using these filters makes it possible to provide a detection sensitivity of (CO2)-C-13 at 5.5 . 10(14) cm(-3) with a minimum detectable fraction of (CO2)-C-13 in a mixture with( 12)CO(2) of the order 2.1 . 10(-5).