Measurement of gas flow velocity: Anemometer with a vibrating hot wire

I propose a new method to measure velocity of a gas flow, which utilizes the time derivative of the voltage observed on a vibrating hot-wire sensor. The wire vibrates with an amplitude a and a frequency f , and is kept perpendicular to the gas flow direction in the plane containing the flow velocity vector v g . When the parameters of vibrations are tuned, the number of zeros per vibration period of the hot-wire voltage function changes. I demonstrate that at the point of change, the unknown gas velocity is directly expressed by the parameters of vibrations v g = 2 π f a . Therefore, the velocity can be measured without any prior calibration of the hot-wire speed-voltage curve and the method can be used for gases of slowly changing temperature or composition.