We Measure the Wind Differently Here

Pitot static tubes are typically used on airplanes to measure how fast the plane is moving. On Mount Washington, we use a pitot tube to measure how fast the air is blowing past the summit. We have used a pitot tube anemometer operationally since 1946 to measure wind for a couple main reasons: it is easily heated to keep it deiced and it has no moving parts that could get damaged by strong winds or heavy icing. The technology is relatively simple and robust through nearly all extreme conditions we experience.

We recently installed a “next-generation” pitot tube anemometer that we expect will be even better than our current operational pitot tube anemometer. But before we can use it operationally, it must go through a minimum 12-month testing phase to determine its robustness and accuracy through the full range of weather conditions. We also need to document each system in terms of its parts and how it works, from the moment wind blows on the pitot tube to the voltage output by the pressure transducer that is used to calculate a wind speed using known temperature, humidity and pressure.

This research project documented all aspects of both pitot static tube systems and started the process of comparing the wind data. Data analysis will continue into next year. All of this work in vitally important for us to be able to say with confidence that the wind speed the next-generation pitot tube anemometer measures is accurate and meets the wind measurement standards set by the National Weather Service and the World Meteorological Organization.

The current operational pitot tub anemometer (left), next-generation anemometer (large black fin, right) and RM Young propeller anemometer (center).