| 摘要 |
PURPOSE:To make it possible to perform the zero adjustment of a smoke densitometer at any time by isolating the path of the light reaching the light-receiving portion from the light source portion from smoke at desired time, with the smoke densitometer mounted on the chimney. CONSTITUTION:The sleeve member 7 having a window and whose left end is secured to the inner surface of a clamping means 13 is provided with a tubular member 1 having a window and which is rotatably fitted. Accordingly, rotating the tubular member 1 relatively to the sleeve member 7 so that the window 2 of the tubular member 1 is aligned with the window 8 of the sleeve member 7 permits the exhaust gas to be freely taken into the inside of the tubular member 1. At said position, the light-receiving portion 5 is actuated to perform measurement. Rotating the tubular member 1 so that the portion of the sleeve member 7 where no window is provided closes the window 2 of the tubular member 1 permits the inside of the tubular member 1 to be isolated from the exhaust gas. Hereupon, purifying air is sent from a purifying air intake 16 to exhaust the inside of the tubular member 1 of the exhaust gas, and then zero adjustment is performed. Thereby, zero adjustment can be performed at any time. |
