Digital speed sensor II for connection to LinkVario Pro.
A pitot speed sensor is required to measure the velocity relative to the incident flow (true airspeed, TAS).
The Digi-Speed-Sensor II (Order No. 4020) or our Pitot-Sensor (Order No. 2560) can be connected directly to the LinkVario Pro.

Especially with the Digi-Speed-Sensor II the speed can also be measured without dynamic pressure nozzle via a tap on the hose connection to the TEK nozzle:
Since the TEK nozzle adds the negative back pressure to the air pressure for compensation, it can also be used for speed measurement. The negative back pressure supplied by our TEK nozzle with coefficient 1 is subtracted from the static pressure in the differential pressure sensor.

With the Pitot Speed Sensor, the outer bores on the ram pressure tube provide the static pressure. Practical experience shows that the static pressure at the sailor's fuselage floor behind the wing also meets these requirements very well. A 1.5 x 0.2mm brass tube flush with the underside of the fuselage provides the static pressure. This must be connected to the Digi-Speed-Sensor II for static pressure. The negative back pressure is taken off via a T-piece in the connecting hose before the TEK connection of the LinkVario Pro and fed to the TEK connection on the Digi-Speed-Sensor II.
In many cases, the static pressure in the fuselage also delivers sufficiently accurate results.
This can be controlled with fast, long-drawn overflights in calm weather compared to GPS speed measurement in the log. This test is quite simple and should always be performed to verify the arrangement.