Integrated Constant Temperature Anemometer for Liquid Flow Rate Measurements

Flow sensors for liquids are relatively expensive devices marked by high insertion losses and low reliability and precision. Integration of a sensor in this class is hindered by the possible damage caused by direct contact with the fluid. In this work we present an anemometer for liquids where a properly designed probe allow a chip, not in direct contact with the fluid, to exchange heat with the latter. The chip includes a complete temperature stabilization loop, while a low cost microcontroller based driver provides the correct timing and signal processing.