In last days Rémi - owner of the website http://voiletech.free.fr developed and tested the TEK probe. This is Bardowiks type probe, mounted veritically to fuselage. This probe type is the least sensitive to variation and divergence angle of attack.
Some photos of real TEK
The mounting socket
Zoom to mounting part
Results of work. Two variometers with identical settings was inside a glider. One was connected to TEK probe, second left uncompensated. We can see some "stick thermics" on sinking phase of flight. Not compensated vario shows all vertical movement of glider and its true altitude. Compensated vario shows signal with substracted part of pressure proportional to flight speed. The faster is glider speed, the bigger underpressure is in probe and bigger compensation effect. Result is much smoother altitude and rate of climb and also higher altitude (because average pressure in probe is lower).
Rémi also developed combined TEK and Pitot probe and made experiments with air speed sensor.