| 摘要 |
The invention provides an apparatus with which the air velocity through (self-regulating) ventilating grates (9) can accurately be measured, without utilizing a wind tunnel, which is costly and occupies much space. The apparatus comprises a tunnel-shaped housing (1, 2, 3, 4) comprising a first compartment having an inlet opening (5) to which a ventilating fan of an adjustable speed can be connected, a measuring partition (8) disposed in transverse direction in the tunnel-shaped housing and in which a ventilating grate (9) can be fitted, and a second compartment, whose walls (1', 2', 3', 4') slant towards each other and define an outflow opening (10) whose surface area is fixedly related to the ventilating capacity of the ventilating grate to be tested, while in a wall of the first compartment at least one ventilating grate (11; 12) is disposed having an air passage opening whose size can be controlled, depending on the pressure prevailing at the inlet side of the ventilating grate to be tested, for keeping this pressure constant. <IMAGE> |
