Pressure-invariant trace gas detection
AssigneeSpectraSensors, Inc.
InventorsXiang Liu, Xin Zhou, Alfred Feitisch, Greg Sanger
Life of this patent
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Abstract
A system includes a light source, a detector, at least one pressure sensor, and a control unit. The light source emits light at a wavelength substantially corresponding to an absorption line of a target gas. The detector is positioned to detect the intensity of light emitted from the light source that has passed through the target gas. The pressure sensor detects the pressure of the target gas. The control circuit is coupled to the detector and the light source to adjust the modulation amplitude of the light source based on the pressure detected by the at least one pressure sensor. Related systems, apparatus, methods, and/or articles are also described.
Claims30
An apparatus comprising;
- at least one light source emitting light at a wavelength substantially corresponding to an absorption line of a target gas;
- at least one detector positioned to detect an intensity of light emitted from the light source that has passed through the target gas at a frequency at a multiple of a modulation frequency of the light source;
- at least one pressure sensor to detect a pressure associated with the target gas;
- and
- a control unit coupled to the at least one detector and the at least one light source to automatically adjust a modulation amplitude of the light source based on the pressure detected by the at least one pressure sensor.
A method of detecting a trace concentration of a target gas within a background gas, the method comprising:
- emitting modulated light at a wavelength substantially corresponding to at least one absorption line of the target gas;
- detecting an intensity of light emitted from the light source that has passed through the target gas at a multiple of a modulation frequency of the emitted light;
- detecting a pressure of the target gas;
- and
- automatically adjusting a modulation amplitude of the modulated light based on the detected pressure of the target gas.
An apparatus comprising;
- a light source emitting light at a wavelength at which molecules and atoms of a target gas absorb light at a substantially greater level than molecules and atoms of a background gas;
- a detector positioned to detect an intensity of light emitted from the light source;
- at least one pressure sensor to detect a pressure associated with the target gas;
- and
- a control unit coupled to the detector and the light source to automatically adjust an operating parameter of the light source based on the pressure detected by the at least one pressure sensor.
Dependencies are inferred from the claim text.