Low-level and ultralow-volume hollow waveguide based carbon monoxide sensor.
We demonstrate an ultralow sample volume optical carbon monoxide sensor with detection sensitivity of 180 parts in 10(9) (1σ at 1 Hz). The utilization of a 2.3 μm surface-emitting laser directly coupled to a 3 m hollow capillary fiber as the gas cell is proven to be a compact, sensitive, and cost-efficient gas sensing concept. By mechanical vibration of the fiber, an absorbance resolution of 10(-5) is achieved, which is comparable to single-reflective (double-pass) cells. An improvement of sensitivity over the conventional single-reflective cell is thus approximately linearly scaled with the enhancement of the optical path length, which is usually more than 1 order of magnitude.
Corporate Research and Technologies, Siemens AG, Otto-Hahn-Ring 6, D-80200 München, Germany. jia.chen@wsi.tum.de
Jia
J
Chen
Andreas
A
Hangauer
Rainer
R
Strzoda
Maximilian
M
Fleischer
Markus-Christian
MC
Amann