An integrated silicon anemometer

Describes some aspects of the research, development and the practical implementation of silicon anemometers based on the measurement of a temperature gradient in an electrically heated piece of silicon, 1.5 mm square. A square Wheatstone bridge consists of four p-type diffused resistors with a sheet resistance of about 300 ohm and with a length-to-width ratio of 45:1. The chip is placed in a fluid with its plane parallel to the fluid to be measured. Based on thermal feedback biasing and the use of CMOS technology a fully integrated sensor can be designed. With the use of etching techniques, both the hot film and the hot wire configuration can be made. Ambient temperature changes can be treated as an independent variable