Patent ID: 7051589
Filing Date: 2006-05-30
Classification: G01F

Abstract:
1. A heating resistor flow rate measuring instrument comprising a heating resistor and a thermally sensitive resistor both disposed in a main passage, and measuring the flow rate of a fluid passing through said main passage, said instrument including: a first sub-passage exposed to the fluid flowing in one direction within said main passage in a larger amount than the fluid flowing in a direction opposite to the one direction; and a second sub-passage exposed to the fluid flowing in the opposite direction within said main passage in a larger amount than the fluid flowing in the one direction, wherein said heating resistor is disposed at said first sub-passage, said thermally sensitive resistor is disposed at said second sub-passage, the flow rate of the fluid passing through said main passage is measured based on amounts of heat radiated from said heating resistor and said thermally sensitive resistor, and the shape of said first sub-passage is different from that of said second sub-passage.