THERMAL-TYPE FLOW VELOCITY SENSOR AND SENSOR SYSTEM USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a thermal-type flow velocity sensor that can burn down (clean) a deposit being deposited to a flow velocity detection element without disturbing measurement of a flow velocity, and a sensor system using the sensor. ;SOLUTION: A flow rate detection element 6 has a resistance electrical heating element 21 and detects the flow rate of a fluid based on the change of the electrical resistance of the resistance electrical heating element 21 for energizing and generating heat due to the direct or indirect contact with the fluid. A cleaning mechanism 22 bums a deposit that is adhered to the flow rate detection element 6 at least partially by a heat being generated by the electrical heating element 22. A cleaning mechanism operation control means starts the generation of heat by the electrical heating element 22 of the flow rate detection element 6 when the flow rate of the fluid to be detected by the flow rate detection element 6 reaches a specific value or less.;COPYRIGHT: (C)1998,JPO