| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an apparatus 1 for measuring an air flow rate capable of improving the detection accuracy by reducing the variation in heat release from a heat generation resistor 4A with an inexpensive means. <P>SOLUTION: A by-pass flow channel 6 having a sensing section 4 is provided with both ends of a bobbin on which the heat generation resistor 4A is wound, and a set of guard sections 8 are disposed on the upstream side of a lead section to be attached to the bobbin. The guard sections 8 are disposed at positions for blocking a part of by-pass flow so that the air flowing into the by-pass flow channel 6 does not directly hit the both ends of the bobbin and the lead section. Thus, part of the air flowing into the by-pass flow channel 6 is blocked by the guard sections 8, and the speed of the air flow hitting the both ends of the bobbin and the lead section significantly reduces, so that the heat release from the both ends of the bobbin is reduced. As a result, the variation in heat release from the heat generation resistor 4A can be kept small, and the flow rate detection accuracy is improved. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
