| 摘要 |
A miniaturized NDIR gas sensor is manufactured using semiconductor micromachining techniques from a semiconductor material such as SI or GaAS. The NDIR gas sensor (28) includes an optical waveguide (30), a light source (32) at one end of the waveguide, at least one light detector (36) at the end of the waveguide opposite the light source, a diffusion type gas sample chamber (34) formed within the waveguide and interposed in the optical path between the light source and light detector so that the light source and light detector are thermally isolated from the gas sample by windows (38, 39), and a separate bandpass filter (52) interposed between the light source and each light detector. Because the NDIR sensor is fabricated out of a semiconductor material, the source driver (76) and signal processing electronics (78) may be added directly to the sensor using integrated circuit fabrication techniques. Particles and smoke and dust may be kept out of the sample chamber by application of a gas permeable membrane (56) over apertures (54) in the sample chamber walls.
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