HEAT-SENSITIVE TYPE FLOW RATE DETECTING ELEMENT AND HOLDER THEREFOR

摘要

The present invention provides a flow rate detecting element which is used for a thermosensitive flow rate sensor to measure the flow rates of various fluids, particularly the intake air of an internal combustion engine. The flow rate detecting element has a thin film layer comprising a support film and a protective film which are made of insulating material and are formed on one surface of a flat substrate, where a heating resistance section and a comparative resistance section are provided by disposing thermosensitive resistor in predetermined patterns between the support film and the protective film of the thin film layer, the flat substrate has a recess which penetrates the flat substrate in the direction of thickness thereof and are formed in at least a part thereof facing the heating resistance section and the comparative resistance section, and a fluid flow passage is provided so as to communicate with the recess which faces the comparative resistance section and let the fluid flow into the recess. Flow rate or velocity of a fluid can be measured accurately by means of the heating resistance section according to the report of the comparative resistance section which senses the fluid temperature with good response characteristic.