The Testo 0635 9435 Vane probe is ideal for velocities ranging from 5 to 40 meters per second.

• Low speed velocity 0 to 5 meters per second
• Medium speed velocity 5 to 40 meters per second
• High speed velocity 40 to 100 meters per second

The measuring principle of the vane probe is based on the conversion of a rotation into electric signals. The flowing agent makes the vane rotate. An inductive proximity switch “counts” the revolutions of the vane and supplies a pulse sequence which is converted in the measuring instrument and is then indicated as a velocity value. Large diameters (Ø 60 millimeters, Ø 100 millimeters) are suitable for the measurement of turbulent flows (e.g. at outlet ducts) at smaller or medium velocities. Small diameters are more suitable for measurements in ducts; in which case the duct cross section must be 100 times bigger than the probe cross section being impacted.