In this paper,a new method of measuring liquid three dimensional flow velocity by rotaining the probe in the plane was submitted basing elaborate analyzing of hot film anemometer.

In this paper, a new method of measuring liquid three dimensional flow velocity by rotating the probe in the plane is presented based on the elaborate analyzing of hot film anemometer.

Temperature-difference type hot-film air mass flow sensor;

Design of hot-film air flow sensor based on method of constant temperature

The heat transfer process of hot-film air mass sensor is analyzed,and the principle of the hot-film air mass flowmeter is discusses,then a circuit is designed.

The results show that the thermal films is composed of FeSO4 and Fe2(SO2)3 under 70℃ and 150℃, the thickness of thermal films can be increased by the raise of temperature and additives sulfur content The components of tribochemical films is the mixture of iron sulfate, pyrite and a mixed intermediate of sulfur, the raise of the additives sulfur conte.

The structure and production process of heat transfer film;