Testo 0563 4171 417 vane anemometer set 1 plus funnel set 0563 4170 testo 0563 4171 p the measurement of flow velocity and the correct calculation of volumetric flow from ventilation outlets can be a challenge the turbulence created and differing flow directions make correct measurement more difficult p p the testo 417 vane anemometer and the testovent 417 measurement funnels provide you with perfect support for flow measurement from ventilation grilles and poppet valves they ensure