| 摘要 |
<p>The radiation from the source (1) is modulated by a rotary shutter disc (2) having filters in its apertures (3,4). The filters generate beams in periodic sequence with different spectral ranges. One range is determined so that the measuring beam is influenced by the gas components to be detected. The other, comparison beam is relatively little or not at all weakened by these gas components. The filters can be interference or gas filters. The radiation path (5) leads to a retro-reflector (9) via a partial mirror (6) and cuvettes (7,8) contg. the gas under test. The reflector (9) returns the radiation through the cuvettes, and by reflection from the mirror (6), to a photo-electric transducer (10). Another rotary disc shutter (11) with two apertures (12,13) operates synchronously with the first shutter (2).</p> |
