The funnels for volume flow measurement allow the determination of volume flow (in m³/h) in combination with thermal or vane anemometers.

The funnels can be used on ventilation systems which withdraw air from rooms via adjustable cross-sections.

Depending on the size of the air vent and the volume flow, it is possible to choose from two selectable funnels. For testovent 410, a maximum edge length of 330 mm and a maximum diameter of 340 mm apply.