| 摘要 |
<p>There is disclosed a gas sensor (1) comprising an electromagnetic radiation source (55), a detector (57) which is sensitive to radiation from the source (57) and a waveguide (14,16,18) which comprises at least a part of an optical path from the source (55) to the detector (57) through a gas sample, the waveguide (14,16,18) comprising a first waveguide portion (14) which extends from the radiation source (55) and a reflector (16) which is arranged to change the direction of and laterally displace radiation conducted from the source (55) through the first waveguide portion (14) into a second waveguide portion (18) which is separate to the first waveguide portion (14) and which conducts received radiation towards the detector (57). The gas sensor (1) can be formed as a layered structure. A convoluted passage (50a,50b) allows gas access to the optical path.</p> |
