Thermal type flow measuring apparatus

摘要

A thermal type flow measuring apparatus includes a heating resistor (10) provided in a thin part (7) of a substrate (2) and a bridge circuit for driving the heating resistor (10) to have a preset heating temperature, wherein resistor elements on sides forming the bridge circuit are temperature sensitive resistors (11, 12, 13), a part or whole of at least one of the temperature sensitive resistors is placed in the thin part (7) and near the heating resistor (10) so that the temperature sensitive resistor is influenced by a heat of the heating resistor (10), and the preset heating temperature is increased as the flow of fluid is increased. This configuration introduces flow dependency into the heating temperature of the heating resistor (10).