Probably the nicest is to utilize the total energy venturi and the dynamic pressure from the pitot tube."[1] As Reichmann explained, a "Netto variometer shows the climb and sink of airmass (not of the sailplane!)...In order to achieve a 'net' indication, the always present polar sink of the sailplane must be 'compensated out' of the indication. To do this, one makes use of the fact that above the speed for best glide the polar sink speed of the sailplane increases roughly with the square of the airspeed. Since the pitot pressure also increases with the square of the speed, one can use it to 'compensate away' the effect of sailplane polar sink over virtually the entire speed range."[2] Tom Brandes states, "Netto is simply the German way of saying 'net,' and a Netto Variometer System (or polar compensator) is simply one that tells you the net vertical air movement with the sailplane movement or sink taken out of the usual variometer reading."[18]