| 摘要 |
PCT No. PCT/SE92/00415 Sec. 371 Date Dec. 3, 1993 Sec. 102(e) Date Dec. 3, 1993 PCT Filed Jun. 12, 1992 PCT Pub. No. WO92/22791 PCT Pub. Date Dec. 23, 1992.A method and apparatus for determining the total flow rate of air flowing through a ventilation installation with a free suction fan (15) is described. The flow rate or a corresponding pressure is determined by measurement of the partial flow rate or a corresponding pressure at at least one measurement point in the vicinity of the inlet opening of the fan. A measurement tube (20) open at both ends is suitably used, and oriented with its longitudinal axis in the inflow direction, flow sensors being arranged inside the measurement tube. In this way, there is obtained good measurement accuracy within a large flow range. |
