HOT WIRE AIR FLOW METER

摘要

A platinum wire (2) is wound in the form of coil. An outer surface of the coiled wire (2) is overcoated with a glass member (4). The coiled wire (2) is welded to supporting member (3). An exothermic resistor (1; 1A, 1B) comprised the coiled wire (12), the glass member (4) and the supporting member (3), and has no bobbin therein. Such an exothermic resistor (1; 1A, 1B) free from a bobbin is used as a hot wire element (1A) and a cold wire element (1B) in a hot wire air flow meter. The quantity of heat generated on the coiled wire (2) hardly transmit through the supporting member (3) and is carried away almost through air. The transient response characteristics under sudden change of an amount of air flow can be improved.