| 摘要 |
<p>- 9 - Case 4341 OPACITY MONITOR An opacity monitor (10) including a light source (12 mounted on one side of a duct (14), and a detector (16) mounted of the opposite side of the duct is disclosed. The light source (12) and the detector (16) are rotated by motor means (267 36), respectively, between a first position aligned with each other along an open light path defined across the duct (14) and a second position aligned with each other on opposite sides of a calibration tube (18) extending across the duct (14). Shutters (28,38) rotate with the light source (12) and the detector (16), respectively, and are aligned with the calibration tube (18) when the light source (12) and the detector (16) are aligned with the open light path, and vice versa.</p> |
