摘要 |
<p>For the controlled ventilation of a room a duct portion (8) with a quantity control and measurement means is provided in the ventilating duct. The duct portion (8) surrounds a tubular hollow body (25) in the form of a flow body, which has two pressure measuring chambers (29, 30) arranged successively in the flow direction. They are provided with rows of openings (27, 28), which produce a connection to the flow cross-sections with different flow speeds. The quantity is measured by means of a differential pressure measuring device (20), which is connected by means of ducts (32, 33) to the pressure measuring chambers (29, 30). The apparatus has low flow losses and a low flow noise. As a result of its favorable flow guidance the apparatus can be positioned directly adjacent to branches of the ventilation duct.</p> |