| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve accuracy and responsiveness with regard to humidity measurement of intake air performed by an air flow rate measuring device 1. <P>SOLUTION: The air flow rate measuring device 1 comprises a humidity sensor 24 which includes a sensing part exposed to an air intake passage, is protruded into the air intake passage from the outer wall of a housing 7 and generates a signal according to the humidity of intake air flowing in the air intake passage. Thus, the sensing part of the humidity sensor 24 is arranged so as to be protruded to the central part of the air intake passage where flow velocity is high, which improves thermal insulation performance from a resin material forming the passage wall of the air intake passage and the housing 7 and reduces the effect of wall surface resistance. Also, because there is a bypass forming part 11 in the housing 7, flow in the air intake passage in the vicinity of the bypass forming part 24 is narrowed and the velocity is increased, which makes more significant the improvement of thermal insulation performance and reduction of the effect of wall resistance on the humidity sensor 24. Consequently, accuracy and responsiveness with regard to humidity measurement of intake air performed by the air flow rate measuring device 1 can be improved. <P>COPYRIGHT: (C)2013,JPO&INPIT |
