TUNABLE DIODE LASER ABSORBPTION SPECTROSCOPY WITH WATER VAPOR DETERMINATION

摘要

A gas absorption spectroscopy system and method are provided. A sealed chamber is provided with a reference gas having a known moisture concentration. An illumination source is disposed in the sealed chamber and is configured to generate an illumination beam. A measurement cell is coupled to the sealed chamber and is configured for exposure to a gas sample such that illumination travelling through the measurement cell passes through the gas sample. A process window is disposed between the sealed chamber and the measurement cell. The process window is configured to receive the illumination beam from the illumination source and reflect a first portion of illumination while allowing a second portion of illumination to pass into the measurement cell. A reference detector is disposed to receive the first portion of illumination and provide a reference detector signal. A measurement detector is disposed to receive the second portion of illumination after the second portion of illumination has passed through the measurement cell and provide a measurement detector signal. A controller is coupled to the reference detector and the measurement detector and is configured to provide a compensated moisture output based on the reference detector signal and the measurement detector signal.

主权项

1. A gas absorption spectroscopy system comprising:
a sealed chamber having a reference gas with a known moisture concentration therein; an illumination source disposed in the sealed chamber and configured to generate an illumination beam; a measurement cell coupled to the sealed chamber and configured for exposure to a gas sample such that illumination travelling through the measurement cell passes through the gas sample; a process window disposed between the sealed chamber and the measurement cell, the process window being configured to receive the illumination beam from the illumination source and reflect a first portion of illumination while allowing a second portion of illumination to pass into the measurement cell; a reference detector disposed to receive the first portion of illumination and provide a reference detector signal; a measurement detector disposed to receive the second portion of illumination after the second portion of illumination has passed through the measurement cell and provide a measurement detector signal; and a controller coupled to the reference detector and the measurement detector, the controller being configured to provide a compensated moisture output based on the reference detector signal and the measurement detector signal.