3-1/8" airspeeds are supplied and marked in MPH and knots scales. Indicators feature 360 degrees sweep for easy reading at a glance. All Winter Airspeeds come complete with mounting screws.
Airspeed-indicators measure the difference between total pressure and static pressure.
The total (or measured) pressure is sensed by a pitot tube positioned at the stagnation point of the airstream and is carried to the airspeed indicator by a hose. A static pressure sensor can also be connected. The measuring element is an open diaphragm unit with excellent elastic properties; hysteresis (differences between advance and return movement) and secondary elastic effects are negligible. The effect total pressure and static pressure acts on the diaphragm, causing a deformation, that is transferred to the pointer by a linkage and gear mechanism. The different operating ranges of the aircraft can be identified by color markings on the airspeed indicator dial. The instruments are insensitive to shock and vibration.
Are Winter ASI instruments TSO'd?
No, they are not TSO'd (certified).