FLOW RATE SENSOR AND FLOW RATE DETECTION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a flow rate sensor capable of enlarging a region in which a flow rate is accurately detectable and improving the symmetry of sensitivity with respect to a direction in which a fluid flows.SOLUTION: A flow rate sensor 10 comprises a bridge circuit 40 having an element group constituted of a pair of differential pressure detection elements 50A and 50B and a diversion passage 26 communicable to a main passage 1 via a pair of ports 23 and 24 and provided with the differential pressure detection elements 50A and 50B. The pair of differential pressure detection elements 50A and 50B are deformable in accordance with the flow of a fluid and each provided with a cantilever part 52 having piezoresistance layers 521 and 522. The cantilever parts 52 of the pair of differential pressure detection elements 50A and 50B are arranged in mutually opposite directions inside the diversion passage 26 so that the fluid is received on faces opposite to each other, and the flow rate of the fluid is detected in accordance with the output of the bridge circuit 40.